Tracker Editor: Alternative way to Add & Delete Entries

Currently, the way to add and delete sequence/track entries on the chain, phrases, songs list is by using:

shift + insert to add an entry
shift + delete to delete an entry

This could be a problem for some users who don't have keyboards with those keys, so there should be another way to adjust these.

I think the current setup we have with arrow keys to navigate, space bar to play the song, and shift + key to edit entries is comfortable. We could optionally bind add and delete to the same key, and just make the logic adjust based on what is already selected: an empty entry will add, and a filled one will delete, etc. I would recommend using the Z key and adding the following commands:

shift + z on an empty entry -> add a new entry
shift + z on an existing entry -> delete the entry

gamercade-io / gamercade_console

Tracker Editor: Alternative way to Add & Delete Entries #64