Doc fixes

[akaszynski]

A few issues that should be resolved with the docs prior to release:

• Icon is missing
• Title should be "Ansys math" and not "Ansys math python libraries"
• Landing page needs to have a bit more information (e.g. background and goal). GitHub README needs to include similar information along with installation directions and a brief example. Consider reusing the readme if not already doing so using the include