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>

templates/repo/clone_buttons.tmpl

@@ -24,7 +24,7 @@
 		const sshButton = document.getElementById('repo-clone-ssh');
 		const httpsButton = document.getElementById('repo-clone-https');
 		const input = document.getElementById('repo-clone-url');
-		if (input) input.value = (isSSH ? sshButton : httpsButton).dataset.link;
+		if (input) input.value = (isSSH ? sshButton : httpsButton).getAttribute('data-link');
 		if (sshButton) sshButton.classList[isSSH ? 'add' : 'remove']('primary');
 		if (httpsButton) httpsButton.classList[isSSH ? 'remove' : 'add']('primary');
 		setTimeout(() => {

templates/repo/empty.tmpl

@@ -51,7 +51,7 @@ git push -u origin {{.Repository.DefaultBranch}}</code></pre>
 								const cloneUrls = document.getElementsByClassName('clone-url');
 								if (cloneUrls) {
 									for (let i = 0; i < cloneUrls.length; i++) {
-										cloneUrls[i].textContent = (isSSH ? sshButton : httpsButton).dataset.link;
+										cloneUrls[i].textContent = (isSSH ? sshButton : httpsButton).getAttribute('data-link');
 									}
 								}
 							</script>