Add glycan_torsion_angles code to examples repo

[OriolAbril]

If possible, add the code used to generate glycan_torsion_angles to https://github.com/arviz-devs/arviz_example_data. @agustinaarroyuelo

[aloctavodia]

@agustinaarroyuelo Did you use bomeba to generate the glycan_torsion_angles example, right? In that case I am a little bit worried about long term maintainability of the example. May be we could switch to a simpler to reproduce example.

[agustinaarroyuelo]

Yes, I did use Bomeba and the example is quite long. I have the same concerns as you

[aloctavodia]

ok then, let's think about a simpler example.