Demonstrate modification of settings.ini

[sdatkinson]

This Issue is for getting some basic proof-of-concept code implemented that makes changes to the settings.ini file. I'd propose simply writing the current installed version of the plugin to the file for the purposes of this Issue to keep it straightforward.

If I can do this, then I can do things like persist settings over multiple plugin instances (e.g. default input calibration, "do not show this again" messages like #425 , etc).