Add testing instructions

Author: jchristgit

guix/README.md

@@ -17,10 +17,21 @@ as a playground for ideas.
   - This is needed for the remote Guix instance to accept packages we build
     locally.
 
+**Testing**
+
+```sh
+# Note that you presently need to run this as root, see
+# https://codeberg.org/guix/guix/issues/4788
+sudo $(guix system container --network machines/turing.scm)
+# This uses your local host network. Use the `guix system container exec`
+# command that prints to get a shell into the container. You can also use
+# `guix system vm` or `guix system image` for a OCI-compatible image.
+```
+
 **Deploying**
 
 ```sh
 # Optional, but recommended
 # guix pull
-guix deploy turing.scm
+guix deploy deployment.scm
 ```