OpenFlops SD Card revisions

[COREi64]

Hi. Forgive me if I've not done this right.

This is the first time I've collaborated on a github and am not sure if my changes will come across to you. If not, please do reach out to me, you have my e-mail address ([email protected]).

Thanks,
Thomas

[SukkoPera]

There are a number of things to fix before this PR can be merged:

1. Please delete the gerbers.SD-MAX.FINAL folder.
2. Please delete the _autosave-OpenFlops.sch file.
3. Since you migrated the project to Kicad 6, some leftover files from Kicad 5 should be removed, which includes the OpenFlops.pro and OpenFlops.sch files at least.
4. The schematics have several issues too, I suggest using the Electrical Rules Check button and fix all the errors it reports, as some are severe.
5. Apparently you didn't include the updated OpenFlops.kicad_pcb file in the PR :).

[SukkoPera]

I have slightly polished the design and removed as many ERC/DRC errors as I could.

Nevertheless, I have decided to keep this PR open for the moment, as I absolutely hate KiCad 6 (this PR migrated the whole design to that) and do not feel confident on what I have done, besides not being able to align/route some things as I would have liked.

Thanks for your contribution anyway, it's not going to be lost.