Use mdbook image to publish mdbook docs

.woodpecker.yml

@@ -2,16 +2,13 @@ platform: linux/arm64
 
 pipeline:
   deployManual:
-    image: rust:1.54.0-slim
+    image: docker.bics.ga/rei_ci/mdbook:latest-arm64
     when:
       branch:
         - develop
     secrets:
       - deploy_ssh_key
     commands: # warning! Doesn't seem to like hashed known_hosts...
-      - cargo install -q mdbook
-      - DEBIAN_FRONTEND=noninteractive apt-get -qq update
-      - DEBIAN_FRONTEND=noninteractive apt-get -yqq install rsync ssh
       - mdbook build
       - echo "$DEPLOY_SSH_KEY" > /tmp/rsync_key
       - chmod u=rw,go= /tmp/rsync_key