Follow new exciting README standard

See coop-cloud/organising#31

README.md

@@ -1,17 +1,33 @@
-# mailu
+# Mailu
 
 Coöp Cloud + [Mailu][Mailu] = 🥳
 
+<!-- metadata -->
+* **Category**: Apps
+* **Status**: ❸🍎
+* **Image**: [`mailu/*`](https://hub.docker.com/r/mailu/), ❶💚, upstream
+* **Healthcheck**: No
+* **Backups**: No
+* **Email**: N/A
+* **Tests**: No
+* **SSO**: No
+<!-- endmetadata -->
+
+NOTE: Mailu requires "host-mode" networking so that containers are aware of
+remote IP addresses. This means that you can only deploy one Mailu instance per
+host.
+
+## Basic usage
+
 1. Set up Docker Swarm and [`abra`][abra]
 2. Deploy [`compose-stacks/traefik`][compose-traefik]
-3. `cp .envrc.sample .envrc`
-4. Edit `.envrc` - be sure to change `$DOMAIN` to something that resolves to
+3. `abra app new mailu`
+4. `abra app YOURAPPDOMAIN config` - be sure to change `$WEB_DOMAIN` to something that resolves to
    your Docker swarm box
-5. `direnv allow` (or `. .envrc`)
-7. `abra deploy`
+5. `abra app YOURAPPDOMAIN deploy`
 9. Create initial user:
 ```
-abra run admin flask mailu admin admin YOURDOMAIN YOURPASSWORD
+abra app YOURAPPDOMAIN run admin flask mailu admin admin YOURDOMAIN YOURPASSWORD
 ```
 
 [Mailu]: https://mailu.io/