Use google style doc strings.

pycharm supports them so there is no need to use the other format.

Might as well convert the existing strings to reduce the risk of
people accidentally cargo culting the wrong doc string format.

synapse/rest/client/v2_alpha/sync.py

@@ -199,15 +199,17 @@ class SyncRestServlet(RestServlet):
         """
         Encode the joined rooms in a sync result
 
-        :param list[synapse.handlers.sync.JoinedSyncResult] rooms: list of sync
-            results for rooms this user is joined to
-        :param int time_now: current time - used as a baseline for age
-            calculations
-        :param int token_id: ID of the user's auth token - used for namespacing
-            of transaction IDs
+        Args:
+            rooms(list[synapse.handlers.sync.JoinedSyncResult]): list of sync
+                results for rooms this user is joined to
+            time_now(int): current time - used as a baseline for age
+                calculations
+            token_id(int): ID of the user's auth token - used for namespacing
+                of transaction IDs
 
-        :return: the joined rooms list, in our response format
-        :rtype: dict[str, dict[str, object]]
+        Returns:
+            dict[str, dict[str, object]]: the joined rooms list, in our
+                response format
         """
         joined = {}
         for room in rooms:
@@ -221,15 +223,17 @@ class SyncRestServlet(RestServlet):
         """
         Encode the invited rooms in a sync result
 
-        :param list[synapse.handlers.sync.InvitedSyncResult] rooms: list of
-             sync results for rooms this user is joined to
-        :param int time_now: current time - used as a baseline for age
-            calculations
-        :param int token_id: ID of the user's auth token - used for namespacing
+        Args:
+            rooms(list[synapse.handlers.sync.InvitedSyncResult]): list of
+                sync results for rooms this user is joined to
+            time_now(int): current time - used as a baseline for age
+                calculations
+            token_id(int): ID of the user's auth token - used for namespacing
             of transaction IDs
 
-        :return: the invited rooms list, in our response format
-        :rtype: dict[str, dict[str, object]]
+        Returns:
+            dict[str, dict[str, object]]: the invited rooms list, in our
+                response format
         """
         invited = {}
         for room in rooms:
@@ -251,15 +255,17 @@ class SyncRestServlet(RestServlet):
         """
         Encode the archived rooms in a sync result
 
-        :param list[synapse.handlers.sync.ArchivedSyncResult] rooms: list of
-             sync results for rooms this user is joined to
-        :param int time_now: current time - used as a baseline for age
-            calculations
-        :param int token_id: ID of the user's auth token - used for namespacing
-            of transaction IDs
+        Args:
+            rooms (list[synapse.handlers.sync.ArchivedSyncResult]): list of
+                sync results for rooms this user is joined to
+            time_now(int): current time - used as a baseline for age
+                calculations
+            token_id(int): ID of the user's auth token - used for namespacing
+                of transaction IDs
 
-        :return: the invited rooms list, in our response format
-        :rtype: dict[str, dict[str, object]]
+        Returns:
+            dict[str, dict[str, object]]: The invited rooms list, in our
+                response format
         """
         joined = {}
         for room in rooms:
@@ -272,17 +278,18 @@ class SyncRestServlet(RestServlet):
     @staticmethod
     def encode_room(room, time_now, token_id, joined=True):
         """
-        :param JoinedSyncResult|ArchivedSyncResult room: sync result for a
-            single room
-        :param int time_now: current time - used as a baseline for age
-            calculations
-        :param int token_id: ID of the user's auth token - used for namespacing
-            of transaction IDs
-        :param joined: True if the user is joined to this room - will mean
-            we handle ephemeral events
+        Args:
+            room (JoinedSyncResult|ArchivedSyncResult): sync result for a
+                single room
+            time_now (int): current time - used as a baseline for age
+                calculations
+            token_id (int): ID of the user's auth token - used for namespacing
+                of transaction IDs
+            joined (bool): True if the user is joined to this room - will mean
+                we handle ephemeral events
 
-        :return: the room, encoded in our response format
-        :rtype: dict[str, object]
+        Returns:
+            dict[str, object]: the room, encoded in our response format
         """
         def serialize(event):
             # TODO(mjark): Respect formatting requirements in the filter.