Add a bracket token on top of the last_bracket stack

Property definitions

markdown2 $ MdInlineParser :: add_bracket
	# Add a bracket token on top of the `last_bracket` stack
	private fun add_bracket(bracket: MdBracket) do
		var last_bracket = self.last_bracket
		if last_bracket != null then
			last_bracket.bracket_after = true
		end
		self.last_bracket = bracket
	end
lib/markdown2/markdown_inline_parsing.nit:630,2--637,4