Consider removing the OAS3-patched directory from the repo

[displague]

Previously we had one file for spec and one file for the patched spec. We now have two folders with hundreds of files for spec and patched spec.

After a conversation with @VamshikShetty, it seems we could remove the patched files from the repo since they are only needed at build time.

We would want to ensure patch creation stays easy, so we may want to copy the source directory to a patch directory first or include documentation to suggest as much.

We may also want to add the working patch directory to .gitignore.