Add Installation and Setup Instructions for Mamba alongside Conda

[sreekarreddydfci]

Update the current installation and setup documentation to include instructions for Mamba without removing the existing Conda instructions.

Resources:

1. https://github.com/mamba-org/mamba

[sreekarreddydfci]

We've updated the installation instructions to include the use of libmamba with Conda, as detailed in this PR: [ #403 ]. This update follows Conda's support for libmamba. For further information on libmamba, see Anaconda's blog post.

I will close this issue once the changes are merged.