Use official crdoc container image

Depends on !164 (merged), fixes #307 (closed).

docs/README.md

@@ -39,5 +39,5 @@ crdoc --resources ../theodolite/crd/ --template api-reference/crds.tmpl  --outpu
 With the following command, crdoc is executed in Docker:
 
 ```sh
-docker run --rm -v "`pwd`/../theodolite/crd/":/crd -u $UID -v "`pwd`/api-reference":/api-reference ghcr.io/fybrik/crdoc:0.6.0 --resources /crd/ --template /api-reference/crds.tmpl --output /api-reference/crds.md
+docker run --rm -v "`pwd`/../theodolite/crd/":/crd -v "`pwd`/api-reference":/api-reference ghcr.io/fybrik/crdoc:0.6.1 --resources /crd/ --template /api-reference/crds.tmpl --output /api-reference/crds.md
 ```