Create a Project section and move several previously
miscategorised reference pages to it.
Move the remaining previously miscategorised reference pages to
the software-contributions directory under the Community section.
Remove Reference section because there is no pertinent content
to put there. In the future, text leveraging the Charmhub to
cite software reference content will be added. This mostly
relates to charm actions and configuration options. The
metadata.yaml file may need to be manually explained due
to this data being missing from the Charmhub.
Add hierarchy to the Community section in terms of software
contributions and documentation contributions.
Rename a few pages (give them better names).
Adjust internal links accordingly.
Add redirects accordingly for older/established pages.
Change-Id: I6b375bd22a62c62fd64a6a83ee0c2d2141e44e23
25ec0cdeaf