Add styles for cheatsheet and hovering with ansys sphinx theme

[Revathyvenugopal162]

This is the new cheat sheet suggested by Mia, updated about font size and styles will be added soon

pinging @ansys/pyansys-core for insights

[AlejandroFernandezLuces]

Columns in the cheatsheet are a bit too close IMO, is it possible/recommendable to add some space between them?

[clatapie]

Is our cheat sheet passing the accessibility check?
I find the green, the violet and the rose quite difficult to read on top of grey.

[Revathyvenugopal162]

Is our cheat sheet passing the accessibility check? I find the green, the violet and the rose quite difficult to read on top of grey.

yes, we need to update the styles for accessibility