* Rename "The walking tour of rustdoc" to "Rustdoc overview",
which I think is a more accurate name
* Use same name in sidebar TOC as in chapter text
* Make links between the two chapters prominent
* Convert a few `.html` links to `.md`
Probably we should just merge the chapters, but leaving that for later.
The biggest change was updating the list of rustdoc passes. Several new
ones have been added since that documentation was written, so I added
those, and I also sorted the list so it is roughly alphabetical (except
for the part for the `strip-*` passes, which I left in the same order
since one of the list items has two passes so there's no "correct"
order).
Justus K
Camelid
Iñaki Garay
Martin Geisler
Nixon Enraght-Moony
Alexis Bourget
Joshua Nelson
Ivan Tham
Guillaume Gomez
Yuki Okushi
Joshua Nelson