Add Waveshare 4.2in B/W e-paper driver

[timboldt]

Like the other EPD drivers in this repo, this driver is a direct port of the Waveshare reference implementation for Arduino, located at https://github.com/waveshare/e-Paper.

[conejoninja]

It looks fine and I assume this is working properly too.
Thanks for your contribution, great addition.

[conejoninja]

One thing missing before merging this PR, is to add the driver to the README.md list and to the smoke-tests (Makefile)

[timboldt]

It looks like I should do something like this? i.e. Add it to the README list, add an example, and add the example to the makefile.

fd9b1ba

[conejoninja]

yes exactly that, have in mind that the number of devices (in README.md file) should be 53. Your base branch has "51", but a new driver was accepted, bumping the number to 52, this driver will be the 53th

[deadprogram]

hI @timboldt can you please also add a smoke test for the new driver like this: https://github.com/tinygo-org/drivers/blob/dev/Makefile#L156-L157

Thank you.

[timboldt]

Will do.

[deadprogram]

Thank you very much for working on this! @timboldt now squash/merging.

[sago35]

link : #181