move "Labrador Developer Documentation" from Google drive to GH repository and update content

[mi-hol]

evolve into a "how to" guide later

@EspoTek checking the Wiki I found a link to Labrador Developer Documentation
Would you mind to move it to our GH repo?

Update:
The challenge for me are the 2 embedded images in "Assembling".
They are represented in markdown as
[image1]: <data:image/png;base64, encoded strings.
Maybe you still have them as files?

I was now comparing the images with my actual board and noticed major differences.
Looks like several revisions of board need pictures & references

Originally posted by @mi-hol in #343

[EspoTek]

Yep, that documentation is very, very, old! It was originally written for the "developer" backers of the Crowd Supply crowdfunding campaign - basically people who got access to prototype hardware and software.

It's mostly outdated but still a useful reference for understanding the specifics of the USB packet specifications (which are mostly unchanged).

[mi-hol]

#243

[EspoTek]

Perhaps not ideal, but I think a link to the public Google Drive is "good enough" given how niche this feature is.