Bazel DevSite: Add link to 5.3.1 docs
toc:
-- label: "5.3"
- path: https://docs.bazel.build/versions/5.3.0/bazel-overview.html
+- label: "5.3.1"
+ path: https://docs.bazel.build/versions/5.3.1/bazel-overview.html
- label: "5.2"
path: https://docs.bazel.build/versions/5.2.0/bazel-overview.html
- label: "5.1.1"
