Add the seal post script into nix file itself.

Some comments on how to use Gitea.
Switching mentions of users to alice

nixos-apps/git.ewanick.com.nix

@@ -25,3 +25,17 @@
     };
   };
 }
+
+
+/*
+  # README
+
+  ## View users and use the command line
+
+  Do something like this, preferably as the gitea user
+
+  ```bash
+  $ sudo su gitea
+  $ /nix/store/5xwh7m7252m9ljvr3lyilcza1q699r2c-gitea-1.17.4/bin/gitea -c /var/lib/gitea/custom/conf/app.ini admin user list
+  ```
+*/