Add a shortcut to invert caps state when writing text

[Tropicalrambler]

Ocasionally, while writing a lot of lines of text, a user will forget to switch CAPS lock and end up with a line like this:

tHE qUICK bROWN fOX jUMPS oVER ...

The idea is to create a javascript function that reverts this with a simple combination keystroke. (pick any) to something like this:

The Quick Brown Fox Jumps Over...

Obviously it is the responsibility of the user to verify caps or no caps when typing, but I believe it is important to provide ease of use tools when we make mistakes.