Update installation docs with PIP package info

[dpascualhe]

We should have two installation tracks:

• Regular users -> pip package
• Developers -> poetry install

Update README and installation instructions in the website accordingly.

[dpascualhe]

@Saiteja-RoshAi

[Saitejabojja07]

@dpascualhe I am interested but a bit confused on how am I supposed to update the installation instructions on the website.