feat: add postgresql example

Signed-off-by: kjuulh <contact@kjuulh.io>

examples/postgres-backed/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "postgres-backed"
+edition = "2024"
+version.workspace = true
+
+[dependencies]
+nocontrol = { workspace = true, features = ["postgres"] }
+nocontrol-tui.workspace = true
+
+anyhow.workspace = true
+tokio.workspace = true
+serde.workspace = true
+tracing-subscriber.workspace = true
+tracing.workspace = true
+rand.workspace = true
+uuid.workspace = true
+noprocess.workspace = true
+tokio-util = { version = "0.7", features = ["rt"] }