Add mamba to installation quick start guide

[jennaswa]

While planning for the ASU workshop (June 2024), @IAlibay highlighted that it would be good to encourage workshop participants to have working mamba installations to speed things up. However, the installation quick start guide only points out conda and pip install options. I wonder if it would be good to incorporate the mamba commands from the installation section in the user guide to make it easier for workshop participants to find the instructions.

[IAlibay]

Linking to MDAnalysis/UserGuide#361