Improve implementation of shift-enter

[dgageot]

Support for shift-enter needs to be improved.

See #875 (comment)

[rockygeekz]

Hi @dgageot ! Can I take this issue and work on it? Thanks!

[dgageot]

@rockygeekz Sure! I'll assign you.

Be careful, not every terminal support shift-enter...
I think that crush uses shift-enter when possible and ctrl-j otherwise (e.g. in Apple's terminal on macOS)

[rockygeekz]

Thank you! I’ll make sure to check the terminal compatibility for Shift-Enter and Ctrl-J. I’ll get started on this now!