Doc files for PyPi installation

[adeliegorce]

This PR includes new doc files to account for the new possibility to install hera_pspec directly from PyPi:

• The main README has been updated from Markdown to ReStructuredText (RST) which is more easily read by PyPi
• The doc files for readthedocs have been slightly changed, and a new Installation section has been added.

[codecov[bot]]

Codecov Report

Base: 95.98% // Head: 95.98% // No change to project coverage :thumbsup:

Coverage data is based on head (5bbc0ba) compared to base (dcba4d4). Patch has no changes to coverable lines.

Additional details and impacted files

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[adeliegorce]

@steven-murray it seems like the tests are failing because of the latest version of hera_cal (I tried with the PyPi distribution and the main branch of the repo)... Any idea what changed? If you want to have a look, the error is triggered when running pytest test_grouping.py in hera_pspec and comes from a ValueError in hera_cal/utils.py

[steven-murray]

@adeliegorce hmm I see. I made https://github.com/HERA-Team/hera_cal/pull/864 to try and fix this.

[steven-murray]

@adeliegorce can you try running these tests on the new branch of hera_cal -- that'll help us know if that branch actually fixes the problem.

[adeliegorce]

There is another ValueError. I am having some trouble tracing it back but it seems like hera_cal.io.load_vis outputs arrays of a different shape than it used to. Does that make sense considering you've modified hera_cal.utils.lst_rephase?

[adeliegorce]

Okay it has to be related because the method failing is pspecdata.rephase_to_dset