Show missing required param message when in standard library format #1339

	name: Generate Roblox standard library
	on: [push, pull_request]
	jobs:
	generate:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v1
	- name: Generate
	run: cargo run --bin selene --verbose -- generate-roblox-std
	- name: Upload
	uses: actions/upload-artifact@v1
	with:
	name: roblox
	path: roblox.yml

Provide feedback