docs(echo): create tutorial (#241)

Author: felangel

docs/docs/tutorials/echo.md

@@ -0,0 +1,163 @@
+---
+sidebar_position: 2
+description: Build a simple "Echo" application.
+---
+
+# Echo 🔊
+
+:::info
+**Difficulty**: 🟢 Beginner<br/>
+**Length**: 15 minutes
+
+Before getting started, [read the prerequisites](/docs/overview#prerequisites) to make sure your development environment is ready.
+:::
+
+## Overview
+
+In this tutorial, we're going to build an app that exposes a single endpoint and responds with a dynamic response which echoes the path back.
+
+When we're done, we should be able to make a `GET` request to the `/<message>` endpoint with any `message`:
+
+```bash
+# <message> is "ping"
+curl --request GET \
+  --url http://localhost:8080/ping
+
+# <message> is "pong"
+curl --request GET \
+  --url http://localhost:8080/pong
+```
+
+And our server should respond with the following responses:
+
+```
+HTTP/1.1 200 OK
+Connection: close
+Content-Length: 21
+Content-Type: text/plain; charset=utf-8
+
+
+ping
+
+---
+
+HTTP/1.1 200 OK
+Connection: close
+Content-Length: 21
+Content-Type: text/plain; charset=utf-8
+
+
+pong
+```
+
+## Creating a new app
+
+To create a new Dart Frog app, open your terminal, `cd` into the directory where you'd like to create the app, and run the following command:
+
+```bash
+dart_frog create echo
+```
+
+You should see the following output:
+
+```
+✓ Creating echo (0.1s)
+✓ Installing dependencies (1.7s)
+
+Created echo at ./echo.
+
+Get started by typing:
+
+cd ./echo
+dart_frog dev
+```
+
+## Running the development server
+
+You should now have a directory called `echo` -- `cd` into it:
+
+```bash
+cd echo
+```
+
+Then, run the following command:
+
+```bash
+dart_frog dev
+```
+
+This will start the development server on port `8080`:
+
+```
+✓ Running on http://localhost:8080 (1.3s)
+The Dart VM service is listening on http://127.0.0.1:8181/YKEF_nbwOpM=/
+The Dart DevTools debugger and profiler is available at: http://127.0.0.1:8181/YKEF_nbwOpM=/devtools/#/?uri=ws%3A%2F%2F127.0.0.1%3A8181%2FYKEF_nbwOpM%3D%2Fws
+[hotreload] Hot reload is enabled.
+```
+
+Make sure it's working by opening [http://localhost:8080](http://localhost:8080) in your browser or via `cURL`:
+
+```bash
+curl --request GET \
+  --url http://localhost:8080
+```
+
+If everything succeeded, you should see `Welcome to Dart Frog!`.
+
+## Creating a dynamic route
+
+Now that we have a running application, let's start by deleting the root route since we won't need it for this example:
+
+```bash
+rm routes/index.dart
+```
+
+Next, let's create `routes/[message].dart`:
+
+```bash
+touch routes/[message].dart
+```
+
+:::note
+The square brackets `[...]` indicates that the path segment is dynamic and will match anything. Learn more about [dynamic routes](/docs/basics/routes#dynamic-routes-).
+:::
+
+Finally, let's define an `onRequest` method in the newly created route:
+
+```dart
+import 'package:dart_frog/dart_frog.dart';
+
+Response onRequest(RequestContext context, String message) {
+  return Response(body: message);
+}
+```
+
+:::note
+Since this route handler corresponds to a dynamic route, we will received the parameter as an argument in `onRequest`.
+:::
+
+Save the changes and hot reload should kick in ⚡️
+
+```bash
+[hotreload] - Application reloaded.
+```
+
+Make sure it's working by opening [http://localhost:8080/ping](http://localhost:8080/ping) in your browser or via `cURL`:
+
+```bash
+curl --request GET \
+  --url http://localhost:8080/ping
+```
+
+If everything succeeded, you should see your message echoed back -- in this case, we should see `ping`.
+
+Let's try making a different request by visiting [http://localhost:8080/pong](http://localhost:8080/pong) in your browser or via `cURL`:
+
+```bash
+curl --request GET \
+  --url http://localhost:8080/pong
+```
+
+This time you should see `pong`.
+
+🎉 Congrats, you've created an `echo` application using Dart Frog. View the [full source code](https://github.com/VeryGoodOpenSource/dart_frog/tree/main/examples/echo).

docs/docs/tutorials/hello_world.md

@@ -30,7 +30,6 @@ HTTP/1.1 200 OK
 Connection: close
 Content-Length: 21
 Content-Type: text/plain; charset=utf-8
-Date: Thu, 04 Aug 2022 19:50:12 GMT
 
 
 Welcome to Dart Frog!
@@ -90,4 +89,4 @@ curl --request GET \
 
 If everything succeeded, you should see `Welcome to Dart Frog!`.
 
-🎉 Congrats, you've created a `hello_world` application using Dart Frog. View the full source code [here](https://github.com/VeryGoodOpenSource/dart_frog/tree/main/examples/hello_world).
+🎉 Congrats, you've created a `hello_world` application using Dart Frog. View the [full source code](https://github.com/VeryGoodOpenSource/dart_frog/tree/main/examples/hello_world).