Put the Docker section first in README.md and rework it.

README.md

-# quickref
+# Quickref
 
 Quickref is a global documentation project for Common Lisp libraries. It
 generates a website containing reference manuals for every
@@ -10,7 +10,48 @@ up-to-date with Quicklisp. This repository contains the whole infrastructure
 needed to generate your own version of the website.
 
 
-## Using `quickref`:
+## Using Quickref
+
+In order to generate your local version of the website, you can use Quickref
+either through the provided Docker images, or directly from the source.
+
+### From Docker
+
+This is the simplest way to use Quickref. The Docker image ships with a
+complete build environment that aims to reproduce the one used to create the
+Quicklisp releases. This means it contains (almost) all the dependencies
+needed to build every library available in Quicklisp.
+
+Type this to run Quickref in Docker:
+```
+docker run --name quickref quickref/quickref
+```
+
+This will automatically pull down the image and run Quickref inside it. If you
+have done this before, you may want to make sure you have the latest image by
+typing this first:
+```
+docker pull quickref/quickref
+```
+
+Also, note that you need a running Docker daemon for this to work. The Mac app
+takes care of this automatically. Otherwise, if the pull or run commands above
+fail, you may need to run the deamon yourself, for example with something like
+this:
+```
+sudo dockerd
+```
+
+When Quickref is done (this *will* take a while), you can extract the website
+from the container by typing this:
+```
+docker cp quickref:/home/quickbuilder/quickref .
+```
+
+The website will be located under `quickref/website`.
+
+
+### From the source
 
 From your lisp REPL, just do:
 
@@ -26,27 +67,6 @@ to HTML.
 
 The generated files can by default be found in `$HOME/quickref/`.
 
-## Docker image:
-
-A Docker image is available, it ships with a complete build environment that
-aims to reproduce the one used to create the Quicklisp releases. This means it
-contains (almost) all the dependencies needed to build every library available
-on Quicklisp.
-
-To run quickref from the image just do:
-
-```
-docker pull quickref/quickref
-docker run quickref/quickref
-```
-
-This will run `(quickref:refresh)` in the image.
-
-You can then get the produced files with
-
-```
-docker cp my-container:/home/quickbuilder/quickref .
-```
 
 ## Advanced usage