[Feature request] Add button to quickly copy link to specific section

[Susko3]

Add a button that will copy a link to a specific section on the wiki. The link would be useful when pointing users to a specific section on a page, eg. when someone enters the lyrics source wrong, so you want to point them to the lyrics section on the song entry page.

Example link that should be copied to the clipboard: https://wiki.vocadb.net/docs/songs/song-entry-editing#tab-lyrics
This link already works, but you need to know the magic ID #tab-lyrics (I usually get it from the F12 dev console).

How it looks on github: