Update README.md

README.md

@@ -55,6 +55,19 @@ We're still in a stage where the installation generally requires many manual ste
 
 See [INSTALL.md](/INSTALL.md)
 
+Usage
+-----
+
+Here's how you run the thing, once installed:
+
+```
+/opt/walnut/bin/node /srv/walnut/core/bin/walnut.js
+```
+
+It listens on all addresses, port 3000.
+
+TODO: Add config to restrict listening to localhost.
+
 API
 ---