add automatic notification about software updates

[mi-hol]

Is your feature request related to a problem? Please describe.
few users seem to be aware of new software downloads available on GitHub

Describe the solution you'd like
i.e for Windows make use of "integrate the Updater with GitHub" available since V17.1 of Caphyon/Advanced Installer (currently V16.7 is used)

Describe alternatives you've considered
add code to Labrador app, but why waste time developing a feature that already exists elsewhere in the tooling used

[mi-hol]

Notes:

1. Advanced Installer 19.3 added GH actions (see https://github.com/Caphyon/advinst-github-action)

2. Advanced Installer 21.0
   Prerequisites are reinstalled even if they are already installed when a reboot is triggered in v20.9.1

3. Advanced Installer 21.3 Updated Updater's GitHub integration to search in both per-user ("HKUD") and per-machine ("HKLM") registry hives

4. Advanced Installer 21.9 Resolve the issue with the "Install side-by-side" option not always being preserved on upgrades