Imroved user experience

Added:

• led animations
• press to pause, and hold to stop the process

Some bug fixes and fine adjustments for the resonance of the liquid and the position of the servo motor. A minor adjustment to the 3D file to make the pcb fit.

First release

A bowl to contain and shake ferric chloride for PCB etching.
Features:

• servo motor whose moovements can be adjusted
• button to start, stop and end the process
• buzzer that souns when the timer ended