Add new JS linter rules (#17699)

* Add new JS linter rules

Adds a few useful rules from eslint-plugin-github. Notable changes:

- Forbid dataset usage, its camel-casing behaviour makes it hard to
  grep for attributes.
- Forbid .then() and .catch(), we should generally prefer await for new
  code. For rare cases where they are useful, a eslint-disable-line
  directive can be set.
- Add docs js to linting

* also enable github/array-foreach

* small tweak

Co-authored-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

web_src/js/standalone/swagger.js

@@ -2,7 +2,7 @@ import SwaggerUI from 'swagger-ui-dist/swagger-ui-es-bundle.js';
 import 'swagger-ui-dist/swagger-ui.css';
 
 window.addEventListener('load', async () => {
-  const url = document.getElementById('swagger-ui').dataset.source;
+  const url = document.getElementById('swagger-ui').getAttribute('data-source');
   const res = await fetch(url);
   const spec = await res.json();