add chapter "ownCloud Bug Triaging"

@carlaschroder lots to do still - I'd like feedback especially from Jennifer, but also @dragotin @karlitschek @danimo @LukasReschke @PVince81 and others ;-)

Mostly on the gaps and the questions in there...
To make a note that is enclosed in a colored box, then do this:

.. note::  ipsum lorem hocus pocus

Otherwise, use normal subheads. The double asterisks enclosing a word or phrase make it bold.
Another type of formatting that might look nice for this sections is definition lists, like this:

Identifying external issues
  Bugs can be due to ....

That makes 'Identifying external issues' bold on its own line.  (http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html#definition-lists)