Added watchtower instructions

README.md

@@ -3,7 +3,7 @@ A minimalistic, but batteries-included, up-to-date docker container for running
 
 This container runs [Radicale](https://github.com/Kozea/Radicale) with the official [Radicale Decsync plugin](https://github.com/39aldo39/Radicale-DecSync) internally.
 
-## Usage
+## Quick Start
 
 To run the container, and have it automatically start after rebooting, just do:
 
@@ -22,7 +22,18 @@ You can then just connect to the local CalDav server using this url: [http://loc
 
 When asked for credentials, just enter something random – the server accepts everything as per the defaul configuration, which is fine as long is it is only exposed on the local network.
 
-## Configuration
+### Setting up Automatic Updates (optional)
+To keep the container automatically up to date (using watchtower), use:
+```bash
+docker run -d \
+    --name watchtower-decsync \
+    -v /var/run/docker.sock:/var/run/docker.sock \
+    containrrr/watchtower decsync-caldav
+```
+
+Since Decsync has seen little changes in years however, and is basically only kept in a working state, it should be perfectly fine to not setup auto updates if you just want to have a stable, working setup.
+
+## Advanced Configuration
 Should you want to add further server/Radicale configuration, take a look at the [base image](https://github.com/tomsquest/docker-radicale).
 
 ## A note on maintenance