docs(backend): shuttle

docs/src/02_01_workspace_setup.md

@@ -77,7 +77,7 @@ The `vsc` flag is used in this case to tell `cargo` to not initialize a new git
 Don't worry if you receive the error message below, it is expected. We will fix it later.
 ```
 
-![Workspace Error](./assets/workspace_error.png)
+![Workspace Error](./assets/21/workspace_error.png)
 
 ### Creating the `shuttle` crate
 
@@ -109,7 +109,7 @@ cargo build
 
 You should see something like this:
 
-![Cargo Build](./assets/cargo_build.png)
+![Cargo Build](./assets/21/cargo_build.png)
 
 ```admonish warning
 Don't commit yet as we still have some work to do!
@@ -130,7 +130,7 @@ Aside from that, **remove** all the `.gitignore` files from the crates as they a
 
 This is how it should look like:
 
-![.gitignore](./assets/gitignore.png)
+![.gitignore](./assets/21/gitignore.png)
 
 ## Committing the changes
 

docs/src/02_02_shuttle.md

@@ -0,0 +1,75 @@
+# Exploring Shuttle
+
+Open the `api/shuttle` folder and look for the `src/main.rs` file. This is the entry point of our application.
+
+You'll see something like this:
+
+```rust
+use actix_web::{get, web::ServiceConfig};
+use shuttle_actix_web::ShuttleActixWeb;
+
+#[get("/")]
+async fn hello_world() -> &'static str {
+    "Hello World!"
+}
+
+#[shuttle_runtime::main]
+async fn actix_web(
+) -> ShuttleActixWeb<impl FnOnce(&mut ServiceConfig) + Send + Clone + 'static> {
+    let config = move |cfg: &mut ServiceConfig| {
+        cfg.service(hello_world);
+    };
+
+    Ok(config.into())
+}
+```
+
+Shuttle has generated a simple `hello-world` [Actix-web](https://actix.rs) application for us. 
+
+As you can see, it's pretty straight-forward.
+
+The `actix_web` function is the entry point of our application. It returns a `ShuttleActixWeb` instance that will be used by Shuttle to run our application.
+
+In this function, we're going to configure our different routes. In this case, we only have one route: `/`, which is mapped to the `hello_world` function.
+
+## Let's run it!
+
+In the **root of the project**, run the following command:
+
+```bash
+cargo shuttle run
+```
+
+You should see something like this:
+
+![shuttle_run](./assets/22/cargo_shuttle_run.png)
+
+Now *curl* the `/` route:
+
+```bash
+curl localhost:8000
+```
+
+Or *open* it in your browser.
+
+Hopefully, **you should see a greeting** in your screen! 
+
+And that's how easy it is to create a simple API with [Shuttle](https://www.shuttle.rs)!
+
+```admonish
+We're using [Actix-web](https://actix.rs) as our web framework, but you can any other framework supported by Shuttle.
+
+Check out the [Shuttle documentation](https://docs.shuttle.rs/introduction/welcome) to learn more. Browse through the `Examples` section to see how to use Shuttle with other frameworks.
+
+[Shuttle](https://www.shuttle.rs/) supports the following frameworks:
+- [Actix-web](https://actix.rs)
+- [Axum](https://github.com/tokio-rs/axum)
+- [Salvo](https://next.salvo.rs/)
+- [Poem](https://github.com/poem-web/poem)
+- [Thruster](https://github.com/thruster-rs/Thruster)
+- [Tower](https://github.com/tower-rs/tower)
+- [Warp](https://github.com/seanmonstar/warp)
+- [Rocket](https://rocket.rs)
+- [Tide](https://github.com/http-rs/tide)
+
+```

docs/src/SUMMARY.md

@@ -9,6 +9,7 @@
 # Backend
 - [Backend](./02_backend.md)
   - [Workspace Setup](./02_01_workspace_setup.md)
+  - [Exploring Shuttle](./02_02_shuttle.md)
 
 # Frontend
 - [Frontend](./04_frontend.md)