Add how to uninstall

[lwcorp]

Is your feature request related to a problem? Please describe. GAM's Google Group mentions all it takes to uninstall is:

1. Windows users that installed via the MSI file, use the official uninstallation
2. Anyone else, simply delete the GAM folder

Describe the solution you'd like

1. Add a clear and concise description of uninstallation to https://github.com/jay0lee/GAM/wiki
2. If needed, add what else needs to be done other than deleting the GAM folder

Describe alternatives you've considered At least add a link to https://groups.google.com/g/google-apps-manager/c/N8XH-aRv7eE/m/tkvHuZSoCQAJ which explains the above.

[lwcorp]

Alright, I've added it to the wiki! But I'd appreciate further easy technical instructions to add to the currently very basic cloud uninstallation part, and how to remove possibly leftover environment variables in Windows/Mac.

[kinafu]

GAM 6.5.8 uninstaller component in the installer for windows does not seem to work for me. After I click on uninstall, a new setup window opens and on clicking "Continue" nothing happens.

Screen gif