workspace: Adding bazel build formatter/linter

Adds in buildifier bazel targets that autoformat/lint the entire
WORKSPACE. This can be invoked by running;

'bazel run //:buildifier'

or

'bazel run //:buildifier_test'

Change-Id: Iaaf7f6241e29894eca94aa6b5d0ca3b33255b7f7
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/36160
Reviewed-by: Keir Mierle <keir@google.com>
Commit-Queue: Keir Mierle <keir@google.com>
diff --git a/pw_web_ui/BUILD b/pw_web_ui/BUILD
index 118fba4..3a242a2 100644
--- a/pw_web_ui/BUILD
+++ b/pw_web_ui/BUILD
@@ -11,7 +11,10 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations under
 # the License.
-exports_files(["rollup.config.js"], visibility = ["//:__subpackages__"])
+exports_files(
+    ["rollup.config.js"],
+    visibility = ["//:__subpackages__"],
+)
 
 alias(
     name = "devserver",