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/scene_replication_interface.h

@@ -75,7 +75,7 @@ private:
 	HashSet<ObjectID> spawned_nodes;
 	HashSet<ObjectID> sync_nodes;
 
-	// Pending spawn informations.
+	// Pending spawn information.
 	ObjectID pending_spawn;
 	int pending_spawn_remote = 0;
 	const uint8_t *pending_buffer = nullptr;