Add extra assertions to `tl:optional` #6068

	name: Remark

	on:
	push:
	branches:
	- master
	pull_request:
	branches:
	- master

	jobs:
	remark:
	runs-on: ubuntu-latest

	steps:
	# Setup
	- name: Checkout
	uses: actions/checkout@v3

	- name: Setup Node.js
	uses: actions/setup-node@v3
	with:
	node-version: '16.x'

	- name: Install remark
	run: npm install remark-cli remark-lint remark-lint-maximum-line-length remark-preset-lint-recommended remark-gfm

	# Run
	- name: Check *.md files
	run: git ls-files -z *.md \| xargs -0 -n 1 npx remark -u lint -f > /dev/null

Provide feedback