Create BibTex, Bibatex, CSL files for referencing.

Summary

We need to create official citation files for all of the RTEMS documentation for authors to include easily. Right now we have nothing official that cites all the authors and creators of our documentation.

If we make it easy for others to do so they can simply include whichever file they want.

I'm not sure how to do this quite yest most likely a YAML file and generate the 3 formats from that so we don't have to edit by hand. The raw text can be included in the documentation itself for cutting and pasting as well has have them deployed as individual files on our main website as a catalogue and on docs.rtems.org.