Update ping.md

Updated ping.png|fzz with HC-SR04 sensor replacing infrared sensor.
Adding place holder. Learning how to fork, update and submit pull request.
Updated fritzing

Update Fritzing ping.png and ping.fzz
Revert "Update ping.md"

This reverts commit e0600566ed024a5c7a8824733dbfe176567e7a37.
Update ping.png, ping.fzz

Update Fritzing with a HC-SR04 ultrasonic sensor. Replacing infrared sensor.
Remove "release history" and regenerate example files

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>
Adds Jeff Albrecht <jeffa@iea-software.com> to contributors

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>