Add a setting to disable or configure the behavior of the escape key

[brianpeiris]

The default behavior of the escape key is to reset your progress on a practice session. This is annoying especially with the "Source Code" practice mode, and my particular keyboard mapping, which has the backtick key as an alternative input of my escape key, so I accidentally reset my progress. I know this might be too specific to my setup, but it would be nice to see a setting for it nonetheless.

I might have time to work on it myself if you're open to the idea.

[atamanroman]

I do have a similar issue: I'm learning a new layout on a split ergo and keep hitting ESC instead of SPC by accident which makes learning with keybr impossible.