Rules are silently ignored if not valid JavaScript

[thatsIch]

Describe the bug
Upon writing custom rules, we often encounter that HTMLHint does not notify us about broken rules.

To Reproduce

1. Define a custom rule like

module.exports = HTMLHint > {

};

Expected behavior
Like in #662 it is expected, that at least some warning is shown, which rule could not be loaded.

Additional context

The result is to be expected due to catching all errors regarding rule imports and ignoring them:

HTMLHint/src/cli/htmlhint.ts

Line 210 in e147134

// ignore

[thatsIch]

I saw, that #662 was fixed with bad68d9.
I guess, that the solution could be pretty similar. I am unsure where to put the test-rules.

Maybe a new folder?

• /test/test-rules/valid-rule.js
• /test/test-rules/invalid-rule.js