Add needed configs to make yarn lint commands work

1. Added .eslintignore, .eslintrc.json, .eslintrc.passing.json, .prettierrc.json and .stylelintrc.json configs to theme. It is fully based on drupal core configs.
2. Fixed absolutely all errors and warnings of all css/js. 99% of those errors were related to the order/whitespaces/linebreaks, for 1% of other errors/warnings i did some changes in code manually, like: move js function on top, or replace == by ===, or replace function () {} by () => {} or smth like this. It was minor changes i did, so i tried to not break anything.

Now no errors in code:

$ yarn lint:css && yarn lint:js
yarn run v1.22.4
$ stylelint "css/src/**/*.css"
✨  Done in 1.77s.
yarn run v1.22.4
$ node ./node_modules/eslint/bin/eslint.js .
Warning: React version was set to "detect" in eslint-plugin-react settings, but the "react" package is not installed. Assuming latest React version for linting.
✨  Done in 1.77s.

What was additionally done:
1. Removed package-lock.json - we don't need it. We have and use yarn.lock
2. Added cool command yarn lint-fix which will fix your code automatically, based on linters. Updated also README.md. So before your patch you just need to run yarn lint-fix