Update README with some testing instructions

README.md

@@ -1 +1,20 @@
-Complete install of my home server, originally running on Olimex's Lime2
+# Complete install of my home server, originally running on Olimex's Lime2
+
+## Usage
+
+### Testing
+
+#### lime2-test
+
+The lime2-test machine is a test VM managed by Vagrant.
+To connect, we need to tell Ansible the connection details:
+
+```bash
+vagrant ssh-config > ssh_config
+```
+
+We can now run tasks on the test machine:
+
+```bash
+ansible-playbook playbook.yml -t forgejo -l lime2-test
+```