Fixes #21

The big "The Stacks Project" header already served as a link to the
home page. But I now realize that the capitalization of this header is
not the way we usually write The/the Stacks project. Should I change
this?
Fixes #20

Less verbose links on the page for a bibliography item
Partially addresses #19

The output is less verbose now, and the preview link is on the same
line. It should be a separate link, as the actual result should link to
the tag's page (to get the real preview etc.)

I should make the output for enumerations using the modifications from
0eeac9c962d9c471e59a654dcbd6f34fb0933481
Fixes #22

I don't know why I added that check, but it shouldn't be there as far as
I can tell.
Partially addresses #23

The Look for a tag section is now only displayed in the relevant
situations. Good idea!
Partially addresses #23

Now when you land on the page through a link to a comment, the comments
are unfolded.
Fixes #23

All remarks from #23 are fixed now I think.
Merge branch 'master' of github.com:pbelmans/stacks-website