Make inherited methods appear in groups if applicable

[UlyssesZh]

Description

Make inherited methods appear in groups if applicable. Example:

module Kat

	# @!group DSL Methods

	def eat
	end

	# @!endgroup

	def drink
	end
end

class Mar

	include Kat

	# @!group DSL Methods

	def sleep
	end

	# @!endgroup

	def rest
	end
end

Completed Tasks

• I have read the Contributing Guide.
• The pull request is complete (implemented / written).
• Git commits have been cleaned up (squash WIP / revert commits).
• I wrote tests and ran bundle exec rake locally (if code is attached to PR).