Revert mdbook update

Author: mboersma

docs/book/install-and-build.sh

@@ -23,7 +23,7 @@ cd "${KUBE_ROOT}" || exit 1
 
 os=$(go env GOOS)
 arch=$(go env GOARCH)
-mdBookVersion="v0.4.48"
+mdBookVersion="v0.4.40"
 genCRDAPIReferenceDocsVersion="ee012b7016522a56d9cef3ea9baed3e0cfc8ff0e"
 
 # translate arch to rust's conventions (if we can)