Extend Mastodon API with public endpoint for getting Favorites timeline of any user (#789)

docs/api/pleroma_api.md

@@ -77,7 +77,7 @@ Request parameters can be passed via [query strings](https://en.wikipedia.org/wi
     * `token`: invite token required when the registrations aren't public.
 * Response: JSON. Returns a user object on success, otherwise returns `{"error": "error_msg"}`
 * Example response:
-```
+```json
 {
 	"background_image": null,
 	"cover_photo": "https://pleroma.soykaf.com/images/banner.png",
@@ -187,6 +187,62 @@ See [Admin-API](Admin-API.md)
 }
 ```
 
+## `/api/v1/pleroma/accounts/:id/favourites`
+### Returns favorites timeline of any user
+* Method `GET`
+* Authentication: not required
+* Params:
+    * `id`: the id of the account for whom to return results
+    * `limit`: optional, the number of records to retrieve
+    * `since_id`: optional, returns results that are more recent than the specified id
+    * `max_id`: optional, returns results that are older than the specified id
+* Response: JSON, returns a list of Mastodon Status entities on success, otherwise returns `{"error": "error_msg"}`
+* Example response:
+```json
+[
+  {
+    "account": {
+      "id": "9hptFmUF3ztxYh3Svg",
+      "url": "https://pleroma.example.org/users/nick2",
+      "username": "nick2",
+      ...
+    },
+    "application": {"name": "Web", "website": null},
+    "bookmarked": false,
+    "card": null,
+    "content": "This is :moominmamma: note 0",
+    "created_at": "2019-04-15T15:42:15.000Z",
+    "emojis": [],
+    "favourited": false,
+    "favourites_count": 1,
+    "id": "9hptFmVJ02khbzYJaS",
+    "in_reply_to_account_id": null,
+    "in_reply_to_id": null,
+    "language": null,
+    "media_attachments": [],
+    "mentions": [],
+    "muted": false,
+    "pinned": false,
+    "pleroma": {
+      "content": {"text/plain": "This is :moominmamma: note 0"},
+      "conversation_id": 13679,
+      "local": true,
+      "spoiler_text": {"text/plain": "2hu"}
+    },
+    "reblog": null,
+    "reblogged": false,
+    "reblogs_count": 0,
+    "replies_count": 0,
+    "sensitive": false,
+    "spoiler_text": "2hu",
+    "tags": [{"name": "2hu", "url": "/tag/2hu"}],
+    "uri": "https://pleroma.example.org/objects/198ed2a1-7912-4482-b559-244a0369e984",
+    "url": "https://pleroma.example.org/notice/9hptFmVJ02khbzYJaS",
+    "visibility": "public"
+  }
+]
+```
+
 ## `/api/pleroma/notification_settings`
 ### Updates user notification settings
 * Method `PUT`