Bazel DevSite: Add "versions" tab to switch between Bazel releases.
Bazel DevSite: Add "versions" tab to switch between Bazel releases.

The list of releases is part of a separate file (_toc.yaml) since this allows our release scripts to update the list whenever a new release is being pushed.

PiperOrigin-RevId: 439527057

katre/bazel,katre/bazel,cushon/bazel,cushon/bazel,bazelbuild/bazel,bazelbuild/bazel,cushon/bazel,bazelbuild/bazel,bazelbuild/bazel,cushon/bazel,bazelbuild/bazel,cushon/bazel,bazelbuild/bazel,katre/bazel,katre/bazel,katre/bazel,cushon/bazel,katre/bazel