Add a conda install option for `xai`

[sugatoray]

A conda installation option could be very helpful. I have already started working on this, to add xai to conda-forge.

Conda-forge PR:

• https://github.com/conda-forge/staged-recipes/pull/17601

Once the conda-forge PR is merged, you will be able to install the library with conda as follows:

conda install -c conda-forge xai

:bulb: I will push a PR to update the docs once the package is available on conda-forge.