Return the char at the current input index + 1, or \0

Property definitions

markdown2 $ MdInlineParser :: peek_next
	# Return the char at the current input index + 1, or `\0`
	private fun peek_next: Char do
		if index + 1 < input.length then
			return input.chars[index + 1]
		end
		return '\0'
	end
lib/markdown2/markdown_inline_parsing.nit:307,2--313,4