Add MyAnimeList issue autoclose (#703)

[skip ci] Add MyAnimeList issue autoclose

This rule is intended to automatically close issues that report
problems with linking MAL that would be solved with the standard
solution of updating & changing the default UA.

The RegEx might be too general, but there isn't any neat pattern in
the previously filed issues.

.github/workflows/issue_moderator.yml

@@ -30,6 +30,12 @@ jobs:
                 "ignoreCase": true,
                 "labels": ["Cloudflare protected"],
                 "message": "Refer to the **Solving Cloudflare issues** section at https://mihon.app/docs/guides/troubleshooting/#cloudflare. If it doesn't work, migrate to other sources or wait until they lower their protection."
+              },
+              {
+                "type": "both",
+                "regex": "^.*(myanimelist|mal).*$",
+                "ignoreCase": true,
+                "message": "For issues with linking MyAnimeList, please follow these steps:\n1. Update Mihon to version 0.16.4 or newer\n2. Change your default User-Agent (`More → Settings → Advanced → Default user agent string`)\n3. Close and restart Mihon\n4. Attempt to link MyAnimeList again\n\nIf you had MyAnimeList linked before, try to unlink it first before trying these steps."
               }
             ]
           auto-close-ignore-label: do-not-autoclose