added new app databag (#197)

Databag is a federated chat service that is designed for privacy but
also light weight self-hosting.

repo: https://github.com/balzack/databag

Apps/Databag/docker-compose.yml

@@ -0,0 +1,36 @@
+name: Databag
+services:
+  databag:
+    image: balzack/databag:0.1.5
+    restart: unless-stopped
+    x-casaos:
+      volumes:
+        - container: /var/lib/databag
+          description:
+            en_us: database and asset store
+      ports:
+        - container: '7000'
+          description:
+            en_us: rest api port
+    ports:
+      - target: 7000
+        published: 7000
+        protocol: tcp
+    volumes:
+      - type: bind
+        source: /DATA/AppData/databag/data
+        target: /var/lib/databag
+x-casaos:
+  architectures:
+    - amd64
+    - arm64
+  main: databag
+  description:
+    en_us: Databag is a federated chat app for self-hosting that focuses on user privacy and security; the service includes clients for iOS, Android, and browser.
+  tagline:
+    en_us: Messenger for the Decentralized Web
+  developer: balzack
+  author: Pierre Balzack
+  category: Chat
+  title:
+    en_us: Databag