B2Qt Demo Update - Add E-bike demo

Code: https://codereview.qt-project.org/#/admin/projects/qt-apps/tqtc-demo-ebike

Description that can be used in the Demo Launcher:

"An E-bike instrument cluster concept designed and implemented by Qt. The entire concept is a testament that Qt brings the HMI designers and Software engineers together by using the same tools, allowing them to fast prototyping through collaborative workflow. In addition to that, Qt is optimized for running on low end SoC even the ones that don't have GPU acceleration for graphics."

miluo can you help in finish / tuning the description above, this was your project.