Style: Misc docs and comment style and language fixes

- Removed empty paragraphs in XML.
- Consistently use bold style for "Example:", on a new line.
- Fix usage of `[code]` when hyperlinks could be used (`[member]`, `[constant]`).
- Fix invalid usage of backticks for inline code in BBCode.
- Fix some American/British English spelling inconsistencies.
- Other minor fixes spotted along the way, including typo fixes with codespell.
- Don't specify `@GlobalScope` for `enum` and `constant`.

modules/multiplayer/doc_classes/MultiplayerSynchronizer.xml

@@ -6,9 +6,7 @@
 	<description>
 		By default, [MultiplayerSynchronizer] synchronizes configured properties to all peers.
 		Visibility can be handled directly with [method set_visibility_for] or as-needed with [method add_visibility_filter] and [method update_visibility].
-
 		[MultiplayerSpawner]s will handle nodes according to visibility of synchronizers as long as the node at [member root_path] was spawned by one.
-
 		Internally, [MultiplayerSynchronizer] uses [method MultiplayerAPI.object_configuration_add] to notify synchronization start passing the [Node] at [member root_path] as the [code]object[/code] and itself as the [code]configuration[/code], and uses [method MultiplayerAPI.object_configuration_remove] to notify synchronization end in a similar way.
 	</description>
 	<tutorials>
@@ -19,7 +17,6 @@
 			<param index="0" name="filter" type="Callable" />
 			<description>
 				Adds a peer visibility filter for this synchronizer.
-
 				[code]filter[/code] should take a peer id [int] and return a [bool].
 			</description>
 		</method>