Add t to current template.

Property definitions

nitc $ PrettyPrinterVisitor :: add
	# Add `t` to current template.
	fun add(t: String) do
		if t.is_empty then return
		while wait_addn > 0 do
			tpl.add "\n"
			wait_addn -= 1
		end
		tpl.add t
		current_length += t.length
	end
src/pretty.nit:235,2--244,4