Standardize OLED display

[jamro]

Select a widely available OLED module with predictable dimensions, pinout, and mounting requirements.

[jamro]

Waveshare 0.91 OLED module ordered... waiting for delivery

[jamro]

The Waveshare OLED arrived. The head will be a bit larger with this display, but the Waveshare model should be much easier to source than the one originally used.

I’ll update docs and release the updated models together with a new parametric 3D model that supports a variety of servos #5