Add audio feature blueprints to docs

Author: hach-que

docs/framework/voice_chat.mdx

@@ -114,3 +114,7 @@ You can control the input and output audio devices on the client:
   audio device the user is using for voice chat.
 - <NodeRef name="Get Voice Chat Audio Output Device" pure /> Returns the current
   output audio device the user is using for voice chat.
+- <NodeRef name="Is Global Voice Chat Audio Feature Enabled" pure /> Returns whether
+  the audio feature (like echo cancellation or noise suppression) is currently enabled.
+- <NodeRef name="Set Global Voice Chat Audio Feature Enabled" /> Sets whether the
+  audio feature (like echo cancellation or noise suppression) should be enabled.