github: Mention auxiliary projects and db corruption in issue template (#5081)

Add a section on using the correct issue tracker
Add a section on database corruption

.github/ISSUE_TEMPLATE.md

@@ -11,6 +11,14 @@ requests directly to the developers. Worst case you might get a short
 "that's a bug, please report it on GitHub" response on the forum, in which
 case we thank you for your patience and following our advice. :)
 
+### Please use the correct issue tracker
+
+If your problem relates to a Syncthing wrapper or [sub-project](https://github.com/syncthing) such as [Syncthing for Android](https://github.com/syncthing/syncthing-android/issues), [SyncTrayzor](https://github.com/canton7/synctrayzor) or the [documentation](https://github.com/syncthing/docs/issues), please use their respective issue trackers.
+
+### Does your log mention database corruption?
+
+If your Syncthing log reports panics because of database corruption it is most likely a fault with your system's storage or memory. Affected log entries will contain lines starting with `panic: leveldb`. You will need to delete the index database to clear this, by running `syncthing -reset-database`.
+
 ### Please do post actual bug reports and feature requests.
 
 If your issue is a bug report, replace this boilerplate with a description