Until now, the copyright years were 2024, but it is 13 days that we
have entered 2025! So it has come time to update them.

With this commit, all the ending copyright years have been changed to
2025.

Until now, the copyright years were 2023, but we have entered 2024 and
it was necessary to update them.

With this commit, the second components of the dates have been updated
to 2024.

Until now, we didn't have a clear link to guide new visitors on how to
start using Maneage! The link to the customization checklist was
deeply burried within the text of the top page and was hard to find
for someone who wants to just get started fast.

With this commit, a "Quick start" link has been added to the top menu
of the Maneage webpage. It will directly go to the customization
checklist within 'README-hacking.md' on Gitlab (which will be up to
date; as we don't yet have a complete and independent documentation,
this is the best current reference). Later, when the documentation is
complete, this link will be changed.

This was suggested by Sepideh Eskandarlou.

Until now the internal and visible copyright years were 2022, but we
have moved into 2023.

With this commit, the copyright years have been updated.

Until now, the only suggested way for contact was Savannah and
directly contacting me. But we have recently added Matrix-protocol
based chatrooms, which some people may find easier to use.

With this commit, a link to the general chat room as been added in the
contacts section at the bottom part of all the pages.

Until now, the copyright years were still for 2021!

With this commit, they have been updated to 2022.

From today (September 15th, 2021), I am employed by CEFCA, so it was
necessary to correct the "base" institute of Maneage also. In the
process, I also noticed that we had forgot to update the copyright
year of Maneage in all the pages, so they have also been corrected.

In the initial version of the paper, we had this nice figure to show
the file structure of Maneage, so I thought its good to put it in the
page describing Maneage's file architecture.

Also, the long copyright at the end of the page was summarized into
one line and a link to the GPL has been added.

In the previous commit that the about pages were separated, I missed
setting some of their titles to <h2>, they were <h1> by mistsake.