Add WinGet installation instructions

[banchan86]

Update installation instructions to add WinGet as an alternative installation method, now that Bonsai has been registered with WinGet.

The command winget install bonsai-rx locates Bonsai using the bonsai-rx moniker, which seems to be the simplest and cleanest installation command for people to remember.

Some notes:

• To be more precise, one can use the package ID BonsaiFoundation.Bonsai instead, but I thought it would be too long for people to remember.
• We can add some details on using the -v parameter to specify a version, but in general, I guess we want people to use the latest version of the Bonsai installer when installing Bonsai system-wide.
• For futureproofing, we can add winget upgrade bonsai-rx, but only Bonsai 2.9 is registered so far. I am not sure how this would work on a system with an older Bonsai version installed (<2.9).
• I noticed that Windows Sandbox does not come with WinGet. For people who want to test the command out in Sandbox they have to install WinGet. There will also be an error with msstore as a source, one can remove msstore with winget source remove msstore (msstore does not work in Sandbox without additional steps).
• Depending on enterprise IT policy, WinGet might not be available on certain Windows computers or there might be other issues. To avoid overcomplicating the instructions, I added an external link to the winget-cli repository, as there is a troubleshooting guide.