License unification

[julianstirling]

Unifying the project to one license to avoid the confusion of multiple-probably incompatible licenses.

Removing SPDX copyright header as these are always out of date as new people add to the code. Git BLAME is a more reliable way to see who contributed to a file and when.

[drayde]

okh.toml was created by Robin and CC0.
Can we simply remove the license info on that file?

[julianstirling]

CC0 and unlicense are both public domain so can be use in other code under other licenses. In theory just relicensing the CC0 to CERN-OHL-S is a bit rude, but as soon as we modify it then we are 100% free to be doing so under our license, and it is out of date so we will be modifying it very soon. The other one of Robin's public domain files is already heavily modified by me.

[drayde]

Ok, thanks for the clarification 👍

[jmwright]

I realize that the LICENSES directory had several licenses in it. However, I and others use a LICENSES directory for hardware projects because there is no single license that properly covers documentation, hardware, and software. So you end up with three licenses for the project, with a clarification in the README.

Example LICENSES directory

Mention of multiple licenses in the readme (scroll down to bottom of the readme for the licenses section)

People also seem to be passionate about licenses, and license changes can be contentious.

[julianstirling]

Thanks @jmwright I have moved this to an open issue as I don't want this important discussion to get lost in a closed PR See #63