Configurable key for code block insertion

[abraithwaite]

With #37 , the ability to easily navigate to EOL using ctrl + e was overridden on many systems.

If not, do you have any idea how this may be overridden with a userscript or the likes? I don't have much proficiency in front-end code, so I wouldn't know where to start doing something like that. However, this is disruptive enough that I'd be willing to put in the effort to make it work. It's about ergonomics.

[keithamus]

This is somewhat a duplicate of #51. I think we can safely close this as it is being worked on.