Update CODEOWNERS

CODEOWNERS

@@ -1 +1,13 @@
-. @fwuensche
+# These owners will be the default owners for everything in
+# the repo. Unless a later match takes precedence,
+* @fwuensche
+
+# Order is important; the last matching pattern takes the most
+# precedence. When someone opens a pull request that only
+# modifies JS files, only these and not the global
+# owner(s) will be requested for a review.
+*.js @fwuensche
+
+# In this example, the user owns any files in the src directory
+# at the root of the repository and any of its subdirectories.
+/src/ @fwuensche