new module Notebook

Hi Charlie, I am MR to ask the approval for the addition of new notebook module I have coded.

There is an environment on HAWK

conda activate /home/nicola.delillo/.conda/envs/pesummary-dev

that you can use to run this notebook (on HAWK)

/home/nicola.delillo/notebooks/pesummary.notebook-testing.ipynb 

It should be free to read and copy but please, let me know if you find any problems and I'll chmod that again. You can use the Jupyter LAB from hawk https://ligo.gravity.cf.ac.uk/jupyter/.

I have also rendered it for you here, so you can test and check the feature I have added https://git.ligo.org/nicola.delillo/awesome-ligo/blob/master/pesummary/using_pesummary_in_python_notebooks.ipynb

This is a draft that could become many or one example if you want.

Things to figure out:

1. Of course you might want to tell me if I have to change the coding style or clean the code. Plus suggestions on the way this notebook module should interact. Any comment , please, do that and I'll change according to your request.
2. I have many others Idea, but I guess this is enough material to review and merge. Than we cans speak in the mattermost on new things
3. This is probably the most important, since people asked for tutorial on how to read samples files. At the and of my example notebook, you find "Read Samples from lalinference". I can read the samples and the parameters, but I was wondering if I can call somehow file.samples['parameter_name'] I am sure it can be done. It is just my ignorance. If you can tell me, I will add this to the tutorial and we can present it.
4. I will need to add a submodule notebook.download which can download from our git repos via the SUPEREVENT label , or from GWOSC once Zoheyr tells us the API are ready.

I also modified accordingly the setup.py, and in the MANIFEST I have added a line to include the file .txt from each designed sensitivity (which I have to add more as soon as I know which is the most updated version for every detector)

Hope you will enjoy this :-)