openapi: Move stray custom emoji description into OpenAPI.

templates/zerver/api/upload-custom-emoji.md

@@ -21,29 +21,14 @@
 
 ## Parameters
 
-As described above, the image file to upload must be provided in the
+{generate_api_arguments_table|zulip.yaml|/realm/emoji/{emoji_name}:post}
-request's body.
 
-## Emoji name
-
-The emoji name can only contain letters, numbers, dashes, and spaces.
-Upper and lower case letters are treated the same, and underscores (_)
-are treated the same as spaces (consistent with how the Zulip UI
-handles emoji).
-
-## Maximum file size
-
-The maximum file size for uploads can be configured by the
-administrator of the Zulip server by setting `MAX_EMOJI_FILE_SIZE_MIB`
-in the [server's settings][1]. `MAX_EMOJI_FILE_SIZE_MIB` defaults
-to 5MB.
-
-[1]: https://zulip.readthedocs.io/en/latest/subsystems/settings.html#server-settings
 {generate_parameter_description(/realm/emoji/{emoji_name}:post)}
 
+## Response
 
 {generate_response_description(/realm/emoji/{emoji_name}:post)}
-## Response
+
 #### Example response
 
 {generate_code_example|/realm/emoji/{emoji_name}:post|fixture(200)}

zerver/openapi/zulip.yaml

@@ -6565,14 +6565,31 @@ paths:
         [organization's configuration](https://zulip.com/help/only-allow-admins-to-add-emoji).
 
         `POST {{ api_url }}/v1/realm/emoji/{emoji_name}`
+      x-parameter-description: |
+        As described above, the image file to upload must be provided in the
+        request's body.
+
+        ## Maximum file size
+
+        The maximum file size for uploads can be configured by the
+        administrator of the Zulip server by setting `MAX_EMOJI_FILE_SIZE_MIB`
+        in the [server's settings][1]. `MAX_EMOJI_FILE_SIZE_MIB` defaults
+        to 5MB.
+
+        [1]: https://zulip.readthedocs.io/en/latest/subsystems/settings.html#server-settings
       parameters:
         - name: emoji_name
           required: true
           in: path
           description: |
             The name that should be associated with the uploaded emoji image/gif.
+            The emoji name can only contain letters, numbers, dashes, and spaces.
+            Upper and lower case letters are treated the same, and underscores (_)
+            are treated the same as spaces (consistent with how the Zulip UI
+            handles emoji).
           schema:
             type: string
+          example: smile
       requestBody:
         content:
           multipart/form-data: