GMRT conversion guide

[ruta-k]

We would like to have a GMRT conversion guide in the "Guides" section. I am attaching a small dataset created by my student Arpan Pal for the same. We would also like to contribute the conversion guide page. Thank you.
gmrt.ms.tar.gz

[FedeMPouzols]

Dear @ruta-k , apologies for the delay in processing this. We are finally going through all the "MSv4 Review" items after the panel review took place.
In this branch: https://github.com/casangi/xradio/tree/303-gmrt_conversion_guide I've put
a first version of a GMRT guide based on your example MS (with very generic content, looking similar to other existing guides). You can check it here:
https://github.com/casangi/xradio/blob/303-gmrt_conversion_guide/docs/source/measurement_set/guides/GMRT.ipynb
(or here if you use colab: https://colab.research.google.com/github/casangi/xradio/blob/303-gmrt_conversion_guide/docs/source/measurement_set/guides/GMRT.ipynb).

You can take this branch as starting point, or we could merge it already as it is into xradio main to have some starting point and then you can take it from there. Just let us know. @Jan-Willem added the "gmrt.ms" to our repository of test files and everything is set up, you can use the example MS as you see in this initial notebook.

Note that this branch also adds one stakeholder test case to cover this "gmrt.ms". I thought it would also be advisable to have this kind of dataset covered in the tests. I believe it was created with importuvfits and then a virtual source was added with setjy/usescratch=False?