Add API specification for user recommendation endpoint

appapi.yaml

@@ -83,6 +83,57 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/error'
+  '/user/recommended':
+    get:
+      summary: Get user recommendations.
+      description: >-
+        Returns an array of objects representing verified users that
+        are not friends of the accessing user and not the user.
+        Optionally the maximum number of results can be specified.
+        The default number of recommendations is three.
+        At most ten users are returned at once.
+        The user objects are stripped down to what is necessary
+        to know as an app user.
+      parameters:
+        - name: c
+          description: The number of recommendations to return. Default is three.
+          in: query
+          required: false
+          schema:
+            type: number
+      responses:
+        '200':
+          description: Success
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/userinfo'
+        '400':
+          description: Result count is no number.
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/input-error'
+        '401':
+          description: Authentication failure.
+          content:
+            text/plain:
+              schema:
+                type: string
+        '500':
+          description: The server cannot deliver due to an internal error.
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/internal-error'
+        default:
+          description: Some unexpected error.
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/error'
   '/user/search':
     get:
       summary: Search for users by their username.