Renames the filename so that it accurately reflects its contents
given the changes to the "Recommended setup" page in the previous
commit, and updates all links accordingly.
Windows users end up having to follow an odd chain of links because
the recommended installation instructions live on a different
page than the rest of the instructions about the environment setup.
All the tutorials about recommended install prerequisites for each
platform should be on the same page.
This moves the section about using WSL 2 from the advanced setup page
to the recommended environment setup tutorial page.
Renames sidebar and section titles to more accurately reflect the
information in the Recommended setup vs. the Advanced setup page.
Updates relevant text and links accordingly.
Fixes: #13696.
David Rosa
Anders Kaseorg