* Holding light button on a non-element screen will turn on the light.
* The alarm and led button press moves back to the currently-selected element symbol page rather than the next and previous one
* Usage update
* Added subscreens to periodic table face; added title and faster scrolling
* Resized buf for element display
* Fixed scrolling to work on actual hardware
* Added delay before _loop_text at title and bugfix on elements shorter than 6 char
* Title screen displays when le_mode starts
* Added documentation on usage and removed unneeded variable
