Gmail style button-simulator, with:
* `gb`/`gc` for clicking on the "Book a session" button,
* Upon triggering, automatically focus onto the input box;
* To exit the "Book a session" box, just press "ESC".

* `gd` to delete the upcoming session (two step process: click "x", and click "yes")

And, other keys to jump from one "view" to another:
* `g2`/`g5` to switch between 25m/50m sessions, and other goodies;
* `gw` to toggle Day/Week view;
* `gi` to jump to the invitation "page/tab";
* `ga` to go view all sessions;
* `gh` to go back to "Calendar view" from other places (after `gi` or `ga`, for example)


For other working shortcuts, please see the code.