Improvement: Add search bar to start page

[Charliopoulos]

It is possible to customize the start page in many ways but I did not find the possiblity of adding a search bar.
It would also be awesome if it had autofocus, so that the user can start typing as soon as the page is laoded.

[eikek]

That would be nice, indeed! PRs are very much appreciated, as I won't have time in the near future to look at this.