Update list

[ahoneybun]

This PR does the following:

• It updates the supported model list to follow this page: https://support.system76.com/articles/open-firmware-systems
  as Open Firmware is not on the galp3-c or the darp5.

[jacobgkau]

• Not officially release and not completed code

"Not officially release" is grammatically incorrect, and "not completed code" is very awkward. Try "Not completed or officially released" or just "Unofficial/incomplete".

[jacobgkau]

It also looks like the asterisk needs to be escaped, otherwise it shows up as another list entry.

[jacobgkau]

Can I ask why you went beyond the first commit? This list is preceded with These models are supported and followed by Other models may be in development or available without support, so it seems strange to include unsupported items in the list. I think the only reason these were in the list to begin with was because they were very nearly supported (PRs are still open/work is still ongoing.)

[crawfxrd]

Technically, README.md.in is what should be updated. (The last commit to README.md would need to be synced as well in that case.)

[crawfxrd]

Done in #260.