doc/go1.14: note that module support is ready for production use
The public proxy and checksum database launched with Go 1.13 have been
running smoothly, pkg.go.dev is serving module-aware documentation,
and in 1.14 we have improved the vendoring workflow and finished
Subversion support to reach parity with GOPATH mode for users of those
features, updated documentation (including the “How to Write Go Code”
intro document) and published blog posts describing common modes of
usage, and improved the migration path for existing v2+ modules by
making version resolution less aggressive about "+incompatible" major
versions.
We (always) have more fit-and-finish work to do, but at this point we
believe that module mode will provide a better user experience than
GOPATH mode for most users, including in production use.