Move web server code into server module.

src/main.rs

@@ -2,6 +2,7 @@ pub mod args;
 pub mod layers;
 pub mod mushroom;
 pub mod render;
+pub mod server;
 pub mod translate;
 
 use std::fs::OpenOptions;
@@ -12,18 +13,13 @@ use clap::Parser;
 #[macro_use]
 extern crate rocket;
 
-#[get("/")]
-fn hello() -> &'static str {
-    "Hello, world!"
-}
-
 #[rocket::main]
 async fn main() {
     let args = args::Args::parse();
 
     if args.run_server {
         // If we run as a server, ignore other arguments.
-        let _ = rocket::build().mount("/", routes![hello]).launch().await;
+        server::run_server().await;
         return;
     }
 

src/server.rs

@@ -0,0 +1,14 @@
+extern crate approx;
+
+pub async fn run_server() {
+    rocket::build()
+        .mount("/", routes![hello])
+        .launch()
+        .await
+        .unwrap();
+}
+
+#[get("/")]
+pub fn hello() -> &'static str {
+    "Hello, world!"
+}