add example .env, don't unwrap postgres error but log it

.env.example

@@ -0,0 +1,2 @@
+DATABASE=postgresql://postgres:postgres@localhost/postgres
+PORT=3000

.gitignore

@@ -1,2 +1,3 @@
 /target
 .vscode
+.env

src/main.rs

@@ -9,7 +9,7 @@ use axum::{routing::get, Router};
 use clap::Parser;
 use sqlx::postgres::PgPoolOptions;
 use tower_http::trace::TraceLayer;
-use tracing::debug;
+use tracing::{debug, error, info};
 
 use crate::config::Config;
 use crate::state::AppState;
@@ -26,19 +26,25 @@ async fn main() {
 
     let config = Config::parse();
 
-    let pool = PgPoolOptions::new()
+    let pool = match PgPoolOptions::new()
         .max_connections(500)
         .connect(&config.database)
-        .await
-        .unwrap();
+        .await {
+            Ok(pool) => pool,
+            Err(err) => return error!("Initializing database: {}", err)
+        };
 
     let state = Arc::new(AppState { pool });
 
+    debug!("Building router");
+
     let app = Router::new()
         .route("/", get(|| async { "Hello, World!" }))
         .layer(TraceLayer::new_for_http())
         .with_state(state);
 
+    info!("Listening on port {}", config.port);
+
     let socket = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)), config.port);
     axum::Server::bind(&socket)
         .serve(app.into_make_service())