Various munger changes

* Add analytics munger w/ munge heading
* More link autofixes
* Allow running a subset of munges
* Fix repo root detection
* Only process non-preformatted blocks
* Gendocs no longer adds the analytics link; mungedocs does that in a
  second pass.

hack/lib/util.sh

@@ -149,7 +149,7 @@ kube::util::gen-doc() {
       local link path
       path="${relative_doc_dest}/${file}"
       link=$(kube::util::analytics-link "${path}")
-      echo -e "\n${link}" >> "${tmpdir}/${file}"
+      echo -e "\n\n${link}" >> "${tmpdir}/${file}"
     fi
     # Remove all old generated files from the destination
     if [[ -e "${tmpdir}/${file}" ]]; then