Auto generated docs are **NO LONGER CHECKED IN**, only placeholders.

To generate them, e.g. before exporting docs, run hack/generate-docs.sh.

hack/verify-generated-docs.sh ensures that generated docs are merely the
placeholder text.

hack/update-generated-docs.sh puts the placeholder text in the proper
places.

The old munge behavior is moved into hack/{update|verify}-munge-docs.sh.