Update config.md
Update config.md

The first line of the file was confusing because it referred to Starlark before defining what Starlark was.  I moved the definition to the first line.

Closes #13374.

PiperOrigin-RevId: 369430700

katre/bazel,meteorcloudy/bazel,twitter-forks/bazel,katre/bazel,bazelbuild/bazel,twitter-forks/bazel,perezd/bazel,meteorcloudy/bazel,cushon/bazel,cushon/bazel,perezd/bazel,bazelbuild/bazel,katre/bazel,bazelbuild/bazel,meteorcloudy/bazel,bazelbuild/bazel,katre/bazel,meteorcloudy/bazel,perezd/bazel,katre/bazel,twitter-forks/bazel,meteorcloudy/bazel,perezd/bazel,bazelbuild/bazel,ButterflyNetwork/bazel,ButterflyNetwork/bazel,cushon/bazel,meteorcloudy/bazel,ButterflyNetwork/bazel,meteorcloudy/bazel,ButterflyNetwork/bazel,ButterflyNetwork/bazel,perezd/bazel,perezd/bazel,bazelbuild/bazel,twitter-forks/bazel,twitter-forks/bazel,cushon/bazel,katre/bazel,cushon/bazel,twitter-forks/bazel,cushon/bazel,perezd/bazel,ButterflyNetwork/bazel,twitter-forks/bazel