docs: correct swagger UI config details

Author: alukach

README.md

@@ -132,7 +132,7 @@ The application is configurable via environment variables.
     - **Type:** boolean
     - **Required:** No, defaults to `true`
     - **Example:** `false`, `1`, `True`
-- OpenAPI
+- OpenAPI / Swagger UI
   - **`OPENAPI_SPEC_ENDPOINT`**, path of OpenAPI specification, used for augmenting spec response with auth configuration
     - **Type:** string or null
     - **Required:** No, defaults to `null` (disabled)
@@ -145,11 +145,11 @@ The application is configurable via environment variables.
     - **Type:** JSON object
     - **Required:** No, defaults to `null` (disabled)
     - **Example:** `{"type": "http", "scheme": "bearer", "bearerFormat": "JWT", "description": "Paste your raw JWT here. This API uses Bearer token authorization.\n"}`
-  - **`SWAGGER_UI_ENDPOINT`**, path of Swagger UI, used for augmenting spec response with auth configuration
+  - **`SWAGGER_UI_ENDPOINT`**, path of Swagger UI, used to indicate that a custom Swagger UI should be hosted, typically useful when providing accompanying `SWAGGER_UI_INIT_OAUTH` arguments
     - **Type:** string or null
-    - **Required:** No, defaults to `/api.html`
-    - **Example:** `/api`
-  - **`SWAGGER_UI_INIT_OAUTH`**, initialization options for the [Swagger UI OAuth2 configuration](https://swagger.io/docs/open-source-tools/swagger-ui/usage/oauth2/)
+    - **Required:** No, defaults to `null` (disabled)
+    - **Example:** `/api.html`
+  - **`SWAGGER_UI_INIT_OAUTH`**, initialization options for the [Swagger UI OAuth2 configuration](https://swagger.io/docs/open-source-tools/swagger-ui/usage/oauth2/) on custom Swagger UI
     - **Type:** JSON object
     - **Required:** No, defaults to `null` (disabled)
     - **Example:** `{"clientId": "stac-auth-proxy", "usePkceWithAuthorizationCodeGrant": true}`