Version 1.3.4

- added support for GDEH116T91 960x640 b/w e-paper panel
- GDEH116T91 has only full screen refresh, no wavetable for differential refresh yet
- added support for processor Arduino Nano RP2040 Connect to the examples
- added general fast b/w refresh for capable 3-color displays GDEW0213Z19, GDEW029Z13
- added example GxEPD2x_FastBlackWhiteOnColor.ino for GDEW0213Z19, GDEW029Z13
- evaluation of other fast b/w capable 3-color panels may follow