feat: Example for Sailfish template engine (#528)

Co-authored-by: aaverichev <Aleksandr.Averichev@hermesrussia.ru>
Co-authored-by: Rob Ede <robjtede@icloud.com>

template_engines/handlebars/README.md

@@ -1,12 +1,16 @@
 # Handlebars
 
-This is an example of how to use Actix Web with the [Handlebars templating language](https://crates.io/crates/handlebars), which is currently the most popular crate that achieves this. After starting the server with `cargo run`, you may visit the following pages:
+This is an example of how to use Actix Web with the [Handlebars](https://crates.io/crates/handlebars) templating language, which is currently the most popular crate that achieves this.
+
+## Usage
 
 ```bash
 cd template_engines/handlebars
 cargo run
 ```
 
+After starting the server, you may visit the following pages:
+
 - http://localhost:8080
 - http://localhost:8080/Emma/documents
 - http://localhost:8080/Bob/passwords

template_engines/handlebars/static/templates/index.html

@@ -9,4 +9,4 @@
     <h1>{{name}} example</h1>
     <p>This is an example of how to use {{name}} with Actix-Web.</p>
 </body>
-</html>
+</html>

template_engines/handlebars/static/templates/user.html

@@ -9,4 +9,4 @@
     <h1>Welcome back, {{user}}</h1>
     <p>Here's your {{data}}.</p>
 </body>
-</html>
+</html>