ESIGMAHM integration

[Akash-Maurya-0899]

This PR adds:

1. a demo notebook for using gw_eccentricity with ESIGMAHM
2. gw_eccentricty posterior postprocessing scripts and notebooks for ESIGMAHM

[md-arif-shaikh]

The notebooks under examples (not under examples/postprocessing) are run with github actions. ESIGMAHM note book examples/egw_from_ESIGMAHM_demo.ipynb is failing because it can't find esigmapy. There are two ways to fix it. First one is harder, you have to install it in the workflow. See here for example. The second one is to make the workflow skip this particular notebook for now. It is still usefull to have it in the examples directory. To skip, add your notebook to this list here.

[md-arif-shaikh]

Also, please add your example notebook in the list of notebooks in the README file.

[Akash-Maurya-0899]

The notebooks under examples (not under examples/postprocessing) are run with github actions. ESIGMAHM note book examples/egw_from_ESIGMAHM_demo.ipynb is failing because it can't find esigmapy. There are two ways to fix it. First one is harder, you have to install it in the workflow. See here for example. The second one is to make the workflow skip this particular notebook for now. It is still usefull to have it in the examples directory. To skip, add your notebook to this list here.

I have gone with the easier, second option for now.