Document installation and public PyPy

[andreap-bh]

Describe the bug

1. no link to the readthedocs documentation, neither in the About section of the project nor in the README.MD
2. Improve installation guide by:
   • polishing the installation.md file
   • removing the Installation inside AILAB-BH section, since this package is now public and not hosted on our servers anymore
   • creating a public PyPy

To Reproduce
N/A

Expected behavior
User easily consults documentation on readthedocs, and installs package with pip

Screenshots
No link to documentation in the About section:

Additional context
N/A

[valvgab-bh]

Thanks @andreap-bh. As for the link to the documentation in the README.md, there is an actionable button right below the library name, but I agree it should be made more visible (e.g. in the About section, as you suggest).

I fully agree on the rest. We will try to fix asap. Or you could open a pull request to solve the issue yourself, if you like :)

[valvgab-bh]

@Somasundaram-Palaniappan do you think we could make this wheel name get updated automatically, after publishing a new release?

We should also remove the section "installing inside BH", as Andrea suggests.