Create colophon for inclusion in tex/md

[karthikraman]

Something on the lines of:

This panchaanga was generated using the jyotisham repository (version?) with festival details pulled from adyatithi repository. Current contributors: @vvasuki & @karthikraman

Perhaps mention Computation System in a user-readable format?

[vvasuki]

In case of MD:

• adyatithi festival repos are directly linked. Clear enough.
• Listing contributors and linking to program seems superfluous given that the https://jyotisham.github.io/jyotisha/ is pretty clear in its links to github etc..
• computation system is shown - and seems pretty clear to those who know (though intended mainly for engineering). I doubt that short text can make it clearer. Though, it might be a good idea to link to descriptions of these parameters in the python code/ generated docs.