[Feedback wanted] Custom integration support

[shiftkey]

I've published a new release which has custom integration support (for editors and shells) and would love help with testing this area for any platform-specific quirks, if anyone has scenarios that they want to try out:

• 3.4.4-linuxbeta2

This is accessible from the File | Options menu:

More details about the changes can be found in the upstream PR - https://github.com/desktop/desktop/pull/18954

Thanks to @sergiou87 for shipping this with support for Linux already available!