DEVDOCS-6562 - Updated v3 cart post with image_url (#1117)

<!-- Ticket number or summary of work -->
# [DEVDOCS-6562]


## What changed?
<!-- Provide a bulleted list in the present tense -->
* Added `image_url` to POST V3 Cart

## Release notes draft
Updated POST V3 Cart API Spec to include image_url similar to what
existed in the GET

ping @bigcommerce/dev-docs 


[DEVDOCS-6562]:
https://bigcommercecloud.atlassian.net/browse/DEVDOCS-6562?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

Author: chris-nowicki

reference/carts.v3.yml

@@ -161,6 +161,7 @@ paths:
                       name: table
                       quantity: 1
                       list_price: 30
+                      image_url: 'https://pathtoproductimage/ProductDefault.png'
                       gift_wrapping:
                         wrap_together: true
                         wrap_details:
@@ -192,8 +193,8 @@ paths:
                       option_selections:
                         - option_id: 116
                           option_value:
-                            originalName: "cs_marking_logo_0.jpeg"
-                            temporaryPath: "488_a430fe0afaf236bef64635c53f9a26ae.jpeg"
+                            originalName: 'cs_marking_logo_0.jpeg'
+                            temporaryPath: '488_a430fe0afaf236bef64635c53f9a26ae.jpeg'
         description: |-
           **Examples:**
 
@@ -218,10 +219,10 @@ paths:
               - quantity: 5
                 product_id: 191
                 variant_id: 185
-                option_selections: 
+                option_selections:
                   - option_id: 440
                     option_value: 1743570000
-          With a Variant of Checkbox and Picklist: 
+          With a Variant of Checkbox and Picklist:
             line_items:
               - quantity: 1
                 product_id: 77
@@ -233,15 +234,16 @@ paths:
                   - option_id: 124
                     option_value: 106
                   - option_id: 122
-                    option_value: "Hello"
-                  - option_id: 123 
+                    option_value: 'Hello'
+                  - option_id: 123
                     option_value: 104
           Custom Item:
             custom_items:
               - sku: abc-123
                 name: Custom Product
                 quantity: 1
                 list_price: 10
+                image_url: 'https://pathtoproductimage/ProductDefault.png'
           Options Selections:
             line_items:
               - quantity: 5
@@ -334,6 +336,7 @@ paths:
                       name: Custom Product
                       quantity: 1
                       list_price: 10
+                      image_url: 'https://pathtoproductimage/ProductDefault.png'
         required: true
       tags:
         - Items
@@ -378,7 +381,7 @@ paths:
       summary: Create Cart Redirect URL
       operationId: createCartRedirectURL
   '/carts/{cartId}/items/{itemId}':
-    parameters: 
+    parameters:
       - $ref: '#/components/parameters/Accept'
       - $ref: '#/components/parameters/cartId'
       - name: itemId
@@ -554,7 +557,7 @@ paths:
       summary: Delete Cart Line Item
       operationId: deleteCartLineItem
   '/carts/{cartId}':
-    parameters: 
+    parameters:
       - $ref: '#/components/parameters/Accept'
       - $ref: '#/components/parameters/cartId'
     get:
@@ -644,7 +647,7 @@ paths:
       summary: Delete a Cart
       operationId: deleteCart
   '/carts/settings':
-    parameters: 
+    parameters:
       - $ref: '#/components/parameters/Accept'
     get:
       summary: Get Global Cart Settings
@@ -878,15 +881,15 @@ paths:
       description: |
         Create a cart `Metafield`. 
 
-        If you create an order from a Cart, you can continue referencing the Cart Metafields even if you delete the original Cart. Use the `cart_id` field on the Order to construct the Cart Metafield endpoint. 
+        If you create an order from a Cart, you can continue referencing the Cart Metafields even if you delete the original Cart. Use the `cart_id` field on the Order to construct the Cart Metafield endpoint.
       operationId: createCartMetafield
-      parameters: 
+      parameters:
         - $ref: '#/components/parameters/ContentType'
       requestBody:
         content:
           application/json:
             schema:
-              $ref: '#/components/schemas/MetafieldBase_Post' 
+              $ref: '#/components/schemas/MetafieldBase_Post'
             example:
               permission_set: app_only
               namespace: Sales Department
@@ -904,17 +907,17 @@ paths:
               schema:
                 $ref: '#/components/schemas/MetaFieldCollectionResponse'
               example:
-                data: 
-                  "id": "24"
-                  "key": Staff Name
-                  "value": Sam
-                  "namespace": Sales Department
-                  "permission_set": app_only
-                  "resource_type": cart
-                  "resource_id": b810114d-9926-45b7-bba5-7633b251154b
-                  "description": Name of staff member
-                  "date_created": 2023-11-15T15:16:35+00:00
-                  "date_modified": 2023-11-15T15:16:35+00:00
+                data:
+                  'id': '24'
+                  'key': Staff Name
+                  'value': Sam
+                  'namespace': Sales Department
+                  'permission_set': app_only
+                  'resource_type': cart
+                  'resource_id': b810114d-9926-45b7-bba5-7633b251154b
+                  'description': Name of staff member
+                  'date_created': 2023-11-15T15:16:35+00:00
+                  'date_modified': 2023-11-15T15:16:35+00:00
                 meta: {}
         '400':
           description: Bad Request. Input is invalid.
@@ -980,7 +983,7 @@ paths:
                   value:
                     status: 404
                     title: The resource at that URL is not found.
-                    type: 'https://developer.bigcommerce.com/api-docs/getting-started/api-status-codes' 
+                    type: 'https://developer.bigcommerce.com/api-docs/getting-started/api-status-codes'
       parameters:
         - $ref: '#/components/parameters/PageParam'
         - $ref: '#/components/parameters/LimitParam'
@@ -1055,7 +1058,7 @@ paths:
       responses:
         '204':
           description: |
-            An empty response. 
+            An empty response.
         '404':
           description: |
             Not found (A metafield was not found with this query)
@@ -1124,7 +1127,7 @@ paths:
                     properties:
                       resource_id:
                         type: string
-                        example: "42"
+                        example: '42'
                         description: |
                           The ID for the cart with which the metafield is associated.
                     required:
@@ -1187,7 +1190,7 @@ paths:
                     properties:
                       id:
                         type: string
-                        example: "42"
+                        example: '42'
                         description: |
                           The ID of metafield to update.
                     required:
@@ -2942,10 +2945,10 @@ components:
         query_params:
           type: object
           properties:
-              key:
-                type: string
-              value:
-                type: string
+            key:
+              type: string
+            value:
+              type: string
     Cart_Line_Item_Update_Post:
       type: object
       title: Cart_Line_Item_Update_Post
@@ -3030,17 +3033,22 @@ components:
           name:
             type: string
             minLength: 1
-            maxLength: 250  
+            maxLength: 250
           quantity:
             type: number
           list_price:
             type: number
+          image_url:
+            type: string
+            format: uri
+            description: Image of the product or variant.
       x-examples:
         example-1:
           - sku: string
             name: string
             quantity: 0
             list_price: 0
+            image_url: 'https://pathtoproductimage/ProductDefault.png'
     CartSettings:
       description: Represents all settings related to the shopping cart functionality of a store.
       type: object
@@ -3370,7 +3378,7 @@ components:
           type: string
           description: |
             Determines the visibility and writeability of the field by other API consumers.
-            
+
             | Value | Description |
             | :--- | :--- |
             | `app_only` | Private to the app that owns the field. |
@@ -3439,7 +3447,7 @@ components:
           type: string
           description: |
             Determines the visibility and writeability of the field by other API consumers.
-            
+
             | Value | Description |
             | :--- | :--- |
             | `app_only` | Private to the app that owns the field. |
@@ -3572,7 +3580,7 @@ components:
             type: integer
             description: |
               The unique identifier for the metafield.
-          example: 
+          example:
             - 123
         errors:
           type: array
@@ -3610,8 +3618,8 @@ components:
       description: |
         Error detail response payload for the BigCommerce API.
       example:
-        "1": "Unauthorized to delete"
-        "2": "Metafield does not exist"
+        '1': 'Unauthorized to delete'
+        '2': 'Metafield does not exist'
     WriteCollectionSuccessMeta:
       type: object
       description: Additional data about the response.
@@ -3721,7 +3729,7 @@ components:
         application/json:
           schema:
             type: object
-            properties: 
+            properties:
               data:
                 $ref: '#/components/schemas/Cart_Full'
               meta:
@@ -3768,7 +3776,7 @@ components:
                   cart_url: 'https://store.mybigcommerce.com/cart.php?action=load&id=0aa00afa-a000-00a0-00aae-aa0000f000a0&token=00aaaaa0aa0000000000a000a000f0aa0000afa00aa00afa0a000000000aa0a0'
                   checkout_url: 'https://store.mybigcommerce.com/cart.php?action=loadInCheckout&id=1ea11efe-b111-11d1-11ee-cd1110f111b1&token=00aaaaa0aa0000000000a000a000f0aa0000afa00aa00afa0a000000000aa0a0'
                   embedded_checkout_url: 'https://store.mybigcommerce.com/cart.php?embedded=1&action=loadInCheckout&id=0aa00afa-a000-00a0-00aae-aa0000f000a0&token=00aaaaa0aa0000000000a000a000f0aa0000afa00aa00afa0a000000000aa0a0'
-                meta: 
+                meta:
                   $ref: '#/components/schemas/metaCollection_open'
   parameters:
     Accept:
@@ -3899,15 +3907,15 @@ components:
     date_modified_max:
       name: 'date_modified:max'
       description: |
-        'Query parameter that lets you filter by the maximum date modified created, for example, `2024-05-14T09:34:00` or `2024-05-14`. Returns metafields modified before this date.' 
+        'Query parameter that lets you filter by the maximum date modified created, for example, `2024-05-14T09:34:00` or `2024-05-14`. Returns metafields modified before this date.'
       required: false
       in: query
       schema:
         type: string
     date_modified_min:
       name: 'date_modified:min'
       description: |
-        'Query parameter that lets you filter by the minimum date modified created, for example, `2024-05-14T09:34:00` or `2024-05-14`. Returns metafields modified after this date.' 
+        'Query parameter that lets you filter by the minimum date modified created, for example, `2024-05-14T09:34:00` or `2024-05-14`. Returns metafields modified after this date.'
       required: false
       in: query
       schema:
@@ -3962,13 +3970,13 @@ components:
         | Header | Argument | Description |
         |:-------|:---------|:------------|
         | `X-Auth-Token` | `access_token` | For more about API accounts that generate `access_token`s, see our [Guide to API Accounts](/docs/start/authentication/api-accounts). |
-        
+
         ### Further reading
 
         For example requests and more information about authenticating BigCommerce APIs, see [Authentication and Example Requests](/docs/start/authentication#x-auth-token-header-example-requests).
-        
+
         For more about BigCommerce OAuth scopes, see our [Guide to API Accounts](/docs/start/authentication/api-accounts#oauth-scopes).
-        
+
         For a list of API status codes, see [API Status Codes](/docs/start/about/status-codes).
       type: apiKey
       in: header