resourceloader: Configure eslint to disallow $ and require inside startup

Would help statically detect accidental use of jQuery ($) before
it is defined within startup. It would also let ESLint in my editor
catch the issue I keep running into where I use a local variable
called 'module' in mediawiki.js before it is defined, which it
doesn't detect because 'module' is whitelisted in the project's
main .eslintrc file. None of the predefined globals for regular
modules are available inside the startup module.

Follows-up dec800968.

Bug: T192623
Change-Id: Icc102d59fff8eb7cd3f4d55f5c8b64866f2bc8af