Added skeleton SnappyMail docs. (#2345)

* Added skeleton SnappyMail docs.

* Added missing backtick

* Fixed typo

pages/04.applications/10.docs/rainloop/app_rainloop.md

@@ -14,8 +14,14 @@ routes:
 ### Index
 
 - [Configuration](#configuration)
+  - [CardDAV](#carddav)
+  - [Domains](#domains)
+  - [PGP Keys](#pgp-keys)
+  - [Upgrade](#upgrade)
 - [Useful links](#useful-links)
 
+! **Note:** RainLoop is no longer maintained, you're encouraged to switch to RainLoop's community maintained fork - [SnappyMail](/app_snappymail)
+
 Rainloop is a lightweight webmail.
 
 ## Configuration

pages/04.applications/10.docs/snappymail/app_snappymail.md

@@ -0,0 +1,44 @@
+---
+title: SnappyMail
+template: docs
+taxonomy:
+    category: docs, apps
+routes:
+  default: '/app_snappymail'
+---
+
+![SnappyMail's logo](image://snappymail_logo.png?height=100)
+
+[![Install SnappyMail with YunoHost](https://install-app.yunohost.org/install-with-yunohost.png)](https://install-app.yunohost.org/?app=snappymail) [![Integration level](https://dash.yunohost.org/integration/snappymail.svg)](https://dash.yunohost.org/appci/app/snappymail)
+
+### Index
+
+- [Configuration](#configuration)
+  - [Domains](#domains)
+  - [Upgrade](#upgrade)
+- [Useful links](#useful-links)
+
+SnappyMail is a lightweight webmail, a fork of RainLoop.
+
+## Configuration
+
+To configure it, go to http://DOMAIN.TLD/snappymail/app/?admin
+
+- The default login is: admin
+- The default password is stored in a file located at `/var/www/snappymail/data/_data_/_default_/admin_password.txt`.
+
+### Domains
+Users can use SnappyMail to access mailboxes other than the one provided by YunoHost (e.g. gmail.com or live.com). The option is available through the "account -> add an account" button.
+The administrator must authorize the connection to third party domains, via a white list in the administration interface.
+
+### Upgrade
+To upgrade the app once a new SnappyMail version is available, simply run in a local shell via ssh or otherwise:
+`sudo yunohost app upgrade -u https://github.com/YunoHost-Apps/snappymail_ynh snappymail`
+
+## Useful links
+
++ Website : [snappymail.eu](https://snappymail.eu/)
++ Official documentation : [github.com/the-djmaze/snappymail/wiki](https://github.com/the-djmaze/snappymail/wiki)
++ Demonstration : [Demo](https://snappymail.eu/demo/)
++ Application software repository : [github.com - YunoHost-Apps/snappymail](https://github.com/YunoHost-Apps/snappymail_ynh)
++ Fix a bug or an improvement by creating a ticket (issue) : [github.com - YunoHost-Apps/snappymail/issues](https://github.com/YunoHost-Apps/snappymail_ynh/issues)