What?

This PR adds a npm command to automatically fix the potentially fixable errors.

Why?

When you execute the npm run lint:js command, sometimes it founds some errors:

The output recommends using the --fix parameter to automatically fix the potentially fixable errors.

If you try to use this parameter with the npm run lint:js command, it doesn't work, because it executes the command without the parameter:

How?

This PR adds a new command with this new parameter, npm run lint:js-fix, that tries to automatically fix the potentially fixable errors.

Testing Instructions

1. Add some linting errors in a JavaScript file. E.g., remove the spaces between the brackets and the text.
2. Execute the npm run lint:js to see the errors.
3. Execute the new npm run lint:js-fix to see the errors fixed automatically.

Screenshots or screencast