Introduce handlebars to be able to do templating

src/bin/generate_readme.rs

@@ -6,18 +6,30 @@
 // included at compile time and then run it to generate a new version of
 // README.md.
 
+extern crate handlebars;
+#[macro_use]
+extern crate serde_json;
+
+use handlebars::Handlebars;
+
 use std::fs::File;
 use std::io::prelude::*;
 
 fn main() {
-    let template = include_str!("../../README-template.md");
+    let template = include_str!("../../README-template.hbs");
+    let autogenerated_notice = "This file was autogenerated by the script in src/bin/generate_readme.rs.
+Please edit either the script or the template in README-template.md in
+order to make changes here rather than committing the changes directly.";
 
     let mut generated_readme = File::create("README.md").unwrap();
-    write!(generated_readme, "\
-<!-- This file was autogenerated by the script in src/bin/generate_readme.rs.
-     Please edit either the script or the template in README-template.md in
-     order to make changes here rather than committing the changes directly. -->
 
-").unwrap();
-    write!(generated_readme, "{}", template).unwrap();
+    let hbs = Handlebars::new();
+    write!(
+        generated_readme,
+        "{}",
+        hbs.render_template(
+            template,
+            &json!({ "autogenerated_notice": autogenerated_notice }),
+        ).unwrap()
+    ).unwrap();
 }