Document endpoint /api/player/autocomplete (fix WandererXII#847)

conf/routes

@@ -57,7 +57,7 @@ GET   /player                          controllers.User.list
 GET   /player/top/:nb/:perfKey         controllers.User.topNb(nb: Int, perfKey: String)
 GET   /player/top/week                 controllers.User.topWeek
 GET   /player/online                   controllers.User.online
-GET   /player/autocomplete             controllers.User.autocomplete
+GET   /api/player/autocomplete         controllers.User.autocomplete
 
 GET   /dasher                          controllers.Dasher.get
 

public/doc/lishogi-api.yaml

@@ -2364,6 +2364,60 @@ paths:
               schema:
                 $ref: '#/components/schemas/Crosstable'
 
+  /api/player/autocomplete:
+    get:
+      operationId: apiPlayerAutocomplete
+      summary: Autocomplete usernames
+      description: |
+        Provides autocompletion options for an incomplete username.
+      tags:
+        - Users
+      security: []
+      parameters:
+        - in: query
+          name: term
+          description: The beginning of a username
+          schema:
+            type: string
+            minLength: 3
+          required: true
+        - in: query
+          name: object
+          description: |
+            - `false` returns an array of usernames
+            - `true` returns an object with matching users
+          schema:
+            type: boolean
+            default: false
+        - in: query
+          name: friend
+          description: |
+            Returns followed players matching `term` if any, else returns other players.
+            Requires [OAuth](#tag/OAuth).
+          schema:
+            type: boolean
+      responses:
+        "200":
+          description: An array of players which usernames start with the provided term.
+          headers:
+            Access-Control-Allow-Origin:
+              schema:
+                type: string
+                default: "'*'"
+          content:
+            application/json:
+              schema:
+                oneOf:
+                  - type: array
+                    items:
+                      type: string
+                  - type: object
+                    properties:
+                      result:
+                        type: array
+                        items:
+                          $ref: '#/components/schemas/LightUser'
+
   /api/stream/event:
     get:
       operationId: apiStreamEvent