Serving static assets

Serving static assets (such as HTML files, JS files, or CSS files) is a very common task for a web application. We can make Rocket serve files as well. Let's create the first function to serve a favicon. Previously you might have noticed that some web browsers requested a favicon file from our server, even though we did not explicitly mention it on our served HTML page. Let's look at the steps:

1. In the application root folder, create a folder named static. Inside the static folder, add a file named favicon.png. You can find sample favicon.png files on the internet or use the file from the sample source code for this chapter.
2. In src/main.rs, add a new route:

   routes![
       ...
       routes::favicon,
   ],

3. In src/routes/mod.rs, add a new route handling function to serve favicon.png:

   use rocket::fs::{relative, NamedFile};
   use std::path::Path;
   ...
   #[get("/favicon.png")]
   pub async fn favicon() ->...