The OAT project was gone for a long time, the successor opencit was
also in an unmaintained state for a few years, let's remove this
piece from the doc as it can't provide meaningful instructions to be
useful.
Change-Id: If77e1125c05e2351c757c4397ea524617e91926d
rename included files to not have ".rst" extension,
otherwise they are being scanned for ref targets and found targets are
effectively counted twice (both in file that includes,
and in the file being included), producing a warning/error.
Change-Id: I2eec5b1b16d253998f45e6f0551a92c2ab6f5609
Closes-Bug: #1743780