Rows/columns insert/delete

[rpeshkov]

Add commands for inserting/deleting rows/columns.

In Emacs it's done via following shortcuts: Insert row: M-S-Down Delete row: M-S-Up Insert column: M-S-Right Delete column: M-S-Left

For showcase refer to wiki

[huyz]

I did find commands for moving columns and rows. I figure these operations involve insert and deletion. Yet, I can't find the commands for insert/delete. 🤔