Move library to root of repository

A popular library installation technique is to download the library via GitHub's Clone or download > Download ZIP and then use the Arduino IDE's Sketch > Include Library > Add .ZIP Library on the downloaded file. This requires the library to be in the root of the repository, not in a subfolder. If the library is not in the root of the repository this installation technique fails:

Specified folder/zip file does not contain a valid library

This is the standard repository structure used in all official Arduino libraries:
https://github.com/arduino-libraries

This move is also required if you wanted to add your library to the Arduino Library Manager index, which provides an even easier installation option.

Author: per1234