Document usage of official recorder Docker image

README.md

@@ -23,6 +23,30 @@ be installed with pip (Python 3 with setuptools required):
 
     sudo pip3 install asciinema
 
+### Docker image
+
+asciinema Docker image is based on Ubuntu 16.04 and has the latest version of
+asciinema recorder pre-installed.
+
+    docker pull asciinema/asciinema
+
+When running it don't forget to allocate a pseudo-TTY (`-t`), keep STDIN open
+(`-i`) and mount config directory volume (`-v`):
+
+    docker run --rm -ti -v "$HOME/.config/asciinema":/root/.config/asciinema asciinema/asciinema
+
+Default command run in a container is `asciinema rec`.
+
+There's not much software installed in this image though. In most cases you may
+want to install extra programs before recording. One option is to derive new
+image from this one (start your custom Dockerfile with `FROM
+asciinema/asciinema`). Another option is to start the container with `/bin/bash`
+as the command, install extra packages and manually start `asciinema rec`:
+
+    docker run --rm -ti -v "$HOME/.config/asciinema":/root/.config/asciinema asciinema/asciinema /bin/bash
+    root@6689517d99a1:~# apt-get install foobar
+    root@6689517d99a1:~# asciinema rec
+
 ### Running latest version from master
 
 If none of the above works for you (or you want to help with development) just