docs: make reporting-issues.rst official and delete reporting-bugs.rst

Remove the WIP and two FIXME notes in the text to make it official, as
it's now considered fully ready for consumption. To make sure this
step is okay for people the intent of this change and the latest version
of the text were posted to ksummit-discuss; nobody complained, thus
lets move ahead.

Add a footer to point out people can contact Thorsten directly in case
they find something to improve in the text.

Dear reporting-bugs.rst, I'm sorry to tell you, but that makes you fully
obsolete and we thus have to let you go now. Thank you very much for
your service, you in one form or another have been around for a long
time. I'm sure over the years you got read a lot and helped quite a few
people. But it's time to retire now. Rest in peace.

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Harry Wei <harryxiyou@gmail.com>
CC: Alex Shi <alex.shi@linux.alibaba.com>
CC: Federico Vaga <federico.vaga@vaga.pv.it>
CC: Greg KH <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/49c674c2d304d87e6259063580fda05267e8c348.1617113469.git.linux@leemhuis.info


Signed-off-by: Jonathan Corbet <corbet@lwn.net>