Start a document about helpful debugging information

BUGS.rst

+====
+BUGS
+====
+
+.. _gitlab.com issues: https://gitlab.com/uplex/varnish/slash/-/issues
+
+If you think you have found a bug, please use use `gitlab.com
+issues`_. You might have already done that and come across a link to
+this document.
+
+PLEASE HELP US HELP YOU
+=======================
+
+Depending on the type of bug, please make an effort to provide the
+requested information:
+
+Panics
+------
+
+For a Varnish Panic (crash), please include the full Panic
+message. Please do not use the ``short_panic`` feature.
+
+The Panic message might contain PII like IP adresses, cookies/tokens or even
+passwords. We do not need this information, please redact it.
+
+If you are unsure about sharing it publicly, you can email your Panic
+message to varnish-support@uplex.de\ . In this case, please reference
+the fact that you did in the ticket.
+
+.. _gitlab.com snippets: https://gitlab.com/-/snippets/new
+
+For the following information, you might want to use `gitlab.com
+snippets`_, please put the snippet link in the issue.
+
+Please provide us with the ``objdump -S`` output of exactly the
+``libvmod_slash.so`` file which the panic occured with, e.g.::
+
+  objdump -S ./src/.libs/libvmod_slash.so
+
+If you have a core dump of the panic, please run some ``gdb commands``
+on it::
+
+  cd $YOUR_VARNISH_WORKING_DIRECTORY
+  gdb -ex "thr app all bt" $YOUR_VARNISHD_BINARY core
+
+For a typical installation, the commands would be::
+
+  cd /var/lib/varnish/$(uname -n)
+  gdb -ex "thr app all bt" /usr/sbin/varnishd core
+
+
+Other
+-----
+
+(Instructions need to be written when they become relevant)