ci: add shuttle deployment action

.github/workflows/shuttle.yml

@@ -0,0 +1,15 @@
+name: Shuttle Deploy
+
+on:
+  release:
+    types:
+      - published
+  workflow_dispatch:
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: shuttle-hq/deploy-action@main
+        with:
+          deploy-key: ${{ secrets.SHUTTLE_API_KEY }}

README.md

@@ -1,13 +1,16 @@
 # Sveio
 
 A geography game inspired by [Posio](https://github.com/abrenaut/posio), written in 🔥🚀Rust.
+View the public instance at [sveio.shuttleapp.rs](https://sveio.shuttleapp.rs)!
 
 ## Deployment
 
 > [!IMPORTANT]
 > Sveio does not impose any rate limit itself.
 > You have to do this yourself, with something like nginx.
 
+### Docker
+
 Sveio is available as a docker image. If you use `docker run` you can run the following to start it:
 
 ```bash
@@ -26,6 +29,17 @@ services:
     restart: unless-stopped
 ```
 
+### Shuttle
+
+[Shuttle.rs](https://shuttle.rs) is supported for the demo server.
+To enable shuttle support use the `shuttle` feature.
+
+Deploy with Shuttle:
+
+```shell
+cargo shuttle deploy
+```
+
 ## Configuration
 
 The server uses the following environmental variables, and it also parses the .env file if present: