History of Using light sensors

Editorial review completed.

Fixed spelling and grammar errors. Also gave a better description of whats going on in the code sample.

Text made no sense and seemed out of place. Text had nothing to do with the topic at hand.

Text made no sense and seemed out of place. Text had nothing to do with the topic at hand.

Fix typo - evironment > environment

devicelightevent Web/API/DeviceLightEvent/Using_light_sensors