Update README.md

* Fill-in the metadata section
 * Add a section about e-mail settings
 * Add a link to peertube's website

README.md

@@ -2,15 +2,17 @@
 
 An ActivityPub-federated video streaming platform using P2P directly in your web browser.
 
+https://joinpeertube.org/
+
 <!-- metadata -->
-* **Category**:
+* **Category**: Applications
-* **Status**: 
+* **Status**: ❷💛
-* **Image**: [`peertube`](https://hub.docker.com/r/peertube/peertube)
+* **Image**: [`chocobozzz/peertube`](https://hub.docker.com/r/chocobozzz/peertube)
-* **Healthcheck**: 
+* **Healthcheck**: ❶💚
-* **Backups**: 
+* **Backups**: ❸🍎
-* **Email**: 
+* **Email**: ❶💚
-* **Tests**: 
+* **Tests**: ❌
-* **SSO**: 
+* **SSO**: ❸🍎
 <!-- endmetadata -->
 
 ## Basic usage
@@ -24,5 +26,14 @@ An ActivityPub-federated video streaming platform using P2P directly in your web
 5. `abra app YOURAPPDOMAIN deploy`
 6. Open the configured domain in your browser to finish set-up
 
+## Email
+
+1. Deploy [`postfix-relay`][coop-cloud/postfix-relay]
+2. `abra app YOURAPPDOMAIN config`, and uncomment the email lines; change
+   `PEERTUBE_SMTP_FROM` to make sure the domain is the same as `postfix-relay`'s
+   `$DOMAIN` or in its `$EXTRA_SENDER_DOMAINS`
+3. `abra app YOURAPPDOMAIN deploy`
+
 [`abra`]: https://git.autonomic.zone/autonomic-cooperative/abra
 [`coop-cloud/traefik`]: https://git.autonomic.zone/coop-cloud/traefik
+[`coop-cloud/postfix-relay`]: https://git.autonomic.zone/coop-cloud/postfix-relay