feat: bzlmod setup (#385)

Creates MODULE.bazel and WORKSPACE.bzlmod files to enable bazel-skylib
to work with the `--experimental_enable_bzlmod` flag.

rules_go has been updated as the previously used version is not
available in the BCR.

stardoc has been updated due to a strange issue with Bzlmod enabled that
caused the `diff_test` and `unittest` docs to be generated without any
contents that was magically fixed upon updating.

bazelbuild/bazel-central-registry#124

Co-authored-by: Alexandre Rostovtsev <arostovtsev@google.com>
diff --git a/docs/build_test_doc.md b/docs/build_test_doc.md
index 332dc58..eba4904 100755
--- a/docs/build_test_doc.md
+++ b/docs/build_test_doc.md
@@ -2,7 +2,7 @@
 
 A test verifying other targets build as part of a `bazel test`
 
-<a id="#build_test"></a>
+<a id="build_test"></a>
 
 ## build_test