chore(docs): add a note about enabling the beta experience in Netlify UI (#383)

* chore(docs): add a note about enabling the beta experience in Netlify UI

* notes

Co-authored-by: Jason Barry <[email protected]>
Co-authored-by: Shane Smith-Sahnow <[email protected]>

Author: 3 people

go/plumbing/operations/operations_client.go

@@ -225,14 +225,16 @@ paths:
           $ref: '#/responses/error'
       description: >-
         [Beta] Returns all environment variables for an account or site. An
-        account corresponds to a team in the Netlify UI.
+        account corresponds to a team in the Netlify UI. To use this endpoint,
+        opt in to the beta environment variable experience using the Netlify UI.
     post:
       tags:
         - environmentVariables
       operationId: createEnvVars
       description: >-
         [Beta] Creates new environment variables. Granular scopes are available
-        on Pro plans and above.
+        on Pro plans and above.  To use this endpoint, opt in to the beta environment
+        variable experience using the Netlify UI.
       parameters:
         - in: body
           name: env_vars
@@ -312,14 +314,17 @@ paths:
             $ref: '#/definitions/envVar'
         default:
           $ref: '#/responses/error'
-      description: '[Beta] Returns an individual environment variable.'
+      description: >-
+        [Beta] Returns an individual environment variable. To use this endpoint,
+        opt in to the beta environment variable experience using the Netlify UI.
     put:
       tags:
         - environmentVariables
       operationId: updateEnvVar
       description: >-
         [Beta] Updates an existing environment variable and all of its values.
-        Existing values will be replaced by values provided.
+        Existing values will be replaced by values provided. To use this endpoint,
+        opt in to the beta environment variable experience using the Netlify UI.
       parameters:
         - name: account_id
           description: Scope response to account_id
@@ -393,7 +398,9 @@ paths:
           description: No Content (success)
         default:
           $ref: '#/responses/error'
-      description: '[Beta] Deletes an environment variable.'
+      description: >-
+        [Beta] Deletes an environment variable. To use this endpoint,
+        opt in to the beta environment variable experience using the Netlify UI.
   /accounts/{account_id}/env/{key}/value/{id}:
     delete:
       tags:
@@ -427,7 +434,9 @@ paths:
           description: No Content (success)
         default:
           $ref: '#/responses/error'
-      description: '[Beta] Deletes a specific environment variable value.'
+      description: >-
+        [Beta] Deletes a specific environment variable value. To use this endpoint, 
+        opt in to the beta environment variable experience using the Netlify UI.
   /sites/{site_id}/forms:
     get:
       operationId: listSiteForms