`find_files` had incorrect regexes which led to `genswaggertypedocs`
never being invoked. This commit updates the regex to correctly
look for versioned API types.go files.
Since `genswaggertypedocs` was never invoked, there are many API types
with missing descriptions. This commit lists these `types.go` files
in `hack/.descriptions_failures`.
The `verify-description.sh` script skips running `genswaggertypedocs`
on the files listed in `hack/.descriptions_failures`.
This allows us to start building real dependencies into Makefile.
Leave old hack/* scripts in place but advise to use 'make'. There are a few
rules that call things like 'go run' or 'build/*' that I left as-is for now.
