Fix the formatting of push config section (#8818)

This PR updates the push config's formatting to better align with our [code style guidelines](https://github.com/matrix-org/synapse/blob/develop/docs/code_style.md#configuration-file-format).

changelog.d/8818.doc

@@ -0,0 +1 @@
+Update the formatting of the `push` section of the homeserver config file to better align with the [code style guidelines](https://github.com/matrix-org/synapse/blob/develop/docs/code_style.md#configuration-file-format).

docs/sample_config.yaml

@@ -2251,6 +2251,9 @@ password_providers:
 
 
 
+## Push ##
+
+push:
   # Clients requesting push notifications can either have the body of
   # the message sent in the notification poke along with other details
   # like the sender, or just the event ID and room ID (`event_id_only`).
@@ -2263,8 +2266,10 @@ password_providers:
   # because it is loaded by the app. iPhone, however will send a
   # notification saying only that a message arrived and who it came from.
   #
-#push:
-#  include_content: true
+  # The default value is "true" to include message details. Uncomment to only
+  # include the event ID and room ID in push notification payloads.
+  #
+  #include_content: false
 
 
 # Spam checkers are third-party modules that can block specific actions

synapse/config/push.py

@@ -21,7 +21,7 @@ class PushConfig(Config):
     section = "push"
 
     def read_config(self, config, **kwargs):
-        push_config = config.get("push", {})
+        push_config = config.get("push") or {}
         self.push_include_content = push_config.get("include_content", True)
 
         pusher_instances = config.get("pusher_instances") or []
@@ -49,6 +49,9 @@ class PushConfig(Config):
 
     def generate_config_section(self, config_dir_path, server_name, **kwargs):
         return """
+        ## Push ##
+
+        push:
           # Clients requesting push notifications can either have the body of
           # the message sent in the notification poke along with other details
           # like the sender, or just the event ID and room ID (`event_id_only`).
@@ -61,6 +64,8 @@ class PushConfig(Config):
           # because it is loaded by the app. iPhone, however will send a
           # notification saying only that a message arrived and who it came from.
           #
-        #push:
-        #  include_content: true
+          # The default value is "true" to include message details. Uncomment to only
+          # include the event ID and room ID in push notification payloads.
+          #
+          #include_content: false
         """