0.12.1.002

Add a feature to generate derived files (i.e. *.swiftmodule, *.swiftdoc, *-Swift.h) with a separate action. Also, add output groups for these files so that they can be generate as top-level output.

SHA-256 digest: 051aacafa4d31d242a19e9a0c5b85614579bb6dc27151bcf2b57f314d12b1c82