ci(earthly): Add docs command

Earthfile

-VERSION 0.7
+VERSION --wait-block 0.7
 
 # images builds all container images in the Repository
 images:
@@ -43,3 +43,11 @@ enable-autoupdates:
     LOCALLY
     ARG --required node
     RUN kubectl label node "${node}" upgrade.shivering-isles.com/fedora-autoupdate=true
+
+# docs runs a local mdbook instance using koolbox that will listen on localhost:3000
+docs:
+    WAIT
+        BUILD ./images/koolbox+install
+    END
+    LOCALLY
+    RUN koolbox mdbook serve docs