Use a Docker image from an automated build

This way the docker image shows the repository that was used to generate
the image and people can go to that repo to look at the Dockerfile used.

docs/documentation.md

@@ -71,7 +71,7 @@ The most advanced way to work on a book is to use git to download all the markdo
 1. *(optional)* If you have [Docker](https://www.docker.com/) installed, then at this point you can run the following command and then skip to the "view the book" step below.
 
     ```
-    docker run --rm -v "$PWD":/docs -p 8000:8000 -w /docs seanmadsen/civicrm-mkdocs serve --dirtyreload -a 0.0.0.0:8000
+    docker run --rm -v "$PWD":/docs -p 8000:8000 -w /docs seanmadsen/civicrm-docker-mkdocs serve --dirtyreload -a 0.0.0.0:8000
     ```
 
 1. Install [pip](https://pypi.python.org/pypi/pip) (python package manager)