open dev console with ~
bind "[the key you want the bind to be set to]" "kill"

jump from a: building,tower,house etc.

while jumping off something make sure to press the bind you set it for to commit suicide and jump at the same time

Good job, you jumped like a real chad.

In the main game menu, select Options.
Navigate to the Keyboard tab in the pop-up window that appears.
At the bottom, select Advanced.
Check the Enable developer console box.
Press OK and then Apply to save your changes.