workspace: add buildifier

To run: `bazel run //:buildifier`

To be done: document and automate

Change-Id: I7631e45915d61d2b95b0d8b0d893d0e1de2ccbed
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1847
Reviewed-by: palid <palid@hackerspace.pl>
diff --git a/WORKSPACE b/WORKSPACE
index 42230a3..bc039ce 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -297,3 +297,13 @@
 # viz.js 2.x used by //dc/topo
 load("//third_party:vizjs.bzl", "vizjs_repositories")
 vizjs_repositories()
+
+# buildifier and friends
+http_archive(
+    name = "com_github_bazelbuild_buildtools",
+    sha256 = "ae34c344514e08c23e90da0e2d6cb700fcd28e80c02e23e4d5715dddcb42f7b3",
+    strip_prefix = "buildtools-4.2.2",
+    urls = [
+        "https://github.com/bazelbuild/buildtools/archive/refs/tags/4.2.2.tar.gz",
+    ],
+)