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/features/tablesort.js

@@ -1,6 +1,8 @@
 export default function initTableSort() {
   for (const header of document.querySelectorAll('th[data-sortt-asc]') || []) {
-    const {sorttAsc, sorttDesc, sorttDefault} = header.dataset;
+    const sorttAsc = header.getAttribute('sortt-asc');
+    const sorttDesc = header.getAttribute('sortt-desc');
+    const sorttDefault = header.getAttribute('sortt-default');
     header.addEventListener('click', () => {
       tableSort(sorttAsc, sorttDesc, sorttDefault);
     });