Add page on how to use es lint tools to fix linting.

[finnlewis]

@andybroomfield @millnut any other issues for reference?

[finnlewis]

See - https://github.com/localgovdrupal/localgov_project/pull/184/files#diff-0dc9388fc0e6882425f546c8775ffdfc98d5e96362d36e9f0567e32120e2b614

[andybroomfield]

From localgovdrupal/localgov_alert_banner#404

Install Node if not already

brew install node

From the root folder: first one time install of Drupal front end libraries

cd web/core
npm install

Then switch back to root folder

cd ../..

Then the following commands can be used.
Javascript:

npx eslint@8 --ext .js --resolve-plugins-relative-to=./web/core --fix path/to/module/root/folder

Yaml

npx eslint@8 --ext .yml --resolve-plugins-relative-to=./web/core --fix path/to/module/root/folder

Stylesheets

npx stylelint --ignore-path web/core/.stylelintignore --config web/core/.stylelintrc.json --fix path/to/module/root/folder/**/*.css