Ability to add a title to the links block

[FarisZR]

I use the Links block along with other content in a page, it's not clear to many what the links block is about.

It would be great if we can add a normal title to it, so it can be a bit more clear what it is, and maybe show up in the TOC too.

A hacky way to do it now is to add an item with just a title, but it doesn't show up as proper one(no hyperlink, no Title anchor, etc.), and it's the same size as normal Items.