Update links to now archived btrfs.wiki.kernel.org

[FroggyFlox]

The Btrfs wiki that used to be hosted at btrfs.wiki.kernel.org now redirects to an archive version at https://archive.kernel.org/oldwiki/btrfs.wiki.kernel.org/index.php/Main_Page.html

As we can see on that page this content is no longer updated and thus considered obsolete.

Contents have been/are in the process of being migrated to https://btrfs.readthedocs.io/. We should thus update (when possible) the current links pointing to the now archived wiki to the new one at readthedocs.io.

[FroggyFlox]

We currently have:

file	current link	proposed new target
data_loss.rst	https://btrfs.wiki.kernel.org/index.php/Glossary	https://btrfs.readthedocs.io/en/latest/Glossary.html
data_loss.rst	https://btrfs.wiki.kernel.org/index.php/SysadminGuide	no clear target identified
data_loss.rst	https://btrfs.wiki.kernel.org/index.php/Status	no clear target identified
data_loss.rst	https://btrfs.wiki.kernel.org/index.php/Btrfs_mailing_list	no clear target identified
faq.rst	https://btrfs.wiki.kernel.org/index.php/Main_Page	https://btrfs.readthedocs.io/en/latest/index.html

There are 3 links without clear identical targets in the "new docs"... these should be investigated further before replacing them. For now, the redirect is still ~OK, although the information will soon be out-of-date for some.

[Hooverdan96]

With #447 some of the links have now find a new home.

file | current link | proposed new target -- | -- | -- data_loss.rst | https://btrfs.wiki.kernel.org/index.php/Glossary | https://btrfs.readthedocs.io/en/latest/Glossary.html data_loss.rst | https://btrfs.wiki.kernel.org/index.php/SysadminGuide | https://btrfs.readthedocs.io/en/latest/dev/dev-btrfs-design.html data_loss.rst | https://btrfs.wiki.kernel.org/index.php/Status | https://btrfs.readthedocs.io/en/latest/Status.html data_loss.rst | https://btrfs.wiki.kernel.org/index.php/Btrfs_mailing_list | no clear target identified faq.rst | https://btrfs.wiki.kernel.org/index.php/Main_Page | https://btrfs.readthedocs.io/en/latest/index.html

The btrfs mailing list could just be replaced with the link to here: http://vger.kernel.org/vger-lists.html#linux-btrfs and instructions for subscribing would be via this link: http://vger.kernel.org/majordomo-info.html#taboo

[Hooverdan96]

@FroggyFlox, with all of the links now dispositioned including the mailing list one, I think this issue can now be closed.

[FroggyFlox]

Thanks a lot for all that work, @Hooverdan96! Closing as requested, as fixed by #447.