Added git-repository-icon option

Updated documentation and added tests.

book-example/src/format/config.md

@@ -149,6 +149,10 @@ The following configuration options are available:
 - **playpen:** A subtable for configuring various playpen settings.
 - **search:** A subtable for configuring the in-browser search functionality.
   mdBook must be compiled with the `search` feature enabled (on by default).
+- **git_repository_url:**  A url to the git repository for the book. If provided
+  an icon link will be output in the menu bar of the book.
+- **git_repository_icon:** The FontAwesome icon class to use for the git
+  repository link. Defaults to `fa-github`.
 
 Available configuration options for the `[output.html.playpen]` table:
 

src/config.rs

@@ -440,8 +440,11 @@ pub struct HtmlConfig {
     pub no_section_label: bool,
     /// Search settings. If `None`, the default will be used.
     pub search: Option<Search>,
-    /// Git repository url. If 'None', the git button will not be shown.
+    /// Git repository url. If `None`, the git button will not be shown.
     pub git_repository_url: Option<String>,
+    /// FontAwesome icon class to use for the Git repository link. 
+    /// Defaults to `fa-github` if `None`.
+    pub git_repository_icon: Option<String>,
 }
 
 impl HtmlConfig {
@@ -573,6 +576,8 @@ mod tests {
         curly-quotes = true
         google-analytics = "123456"
         additional-css = ["./foo/bar/baz.css"]
+        git-repository-url = "https://foo.com/"
+        git-repository-icon = "fa-code-fork"
 
         [output.html.playpen]
         editable = true
@@ -610,6 +615,8 @@ mod tests {
             additional_css: vec![PathBuf::from("./foo/bar/baz.css")],
             theme: Some(PathBuf::from("./themedir")),
             playpen: playpen_should_be,
+            git_repository_url: Some(String::from("https://foo.com/")),
+            git_repository_icon: Some(String::from("fa-code-fork")),
             ..Default::default()
         };
 

src/renderer/html_handlebars/hbs_renderer.rs

@@ -455,8 +455,13 @@ fn make_data(
     }
 
     if let Some(ref git_repository_url) = html_config.git_repository_url {
-        data.insert("git-repository-url".to_owned(), json!(git_repository_url));
+        data.insert("git_repository_url".to_owned(), json!(git_repository_url));
     }
+    let git_repository_icon = match html_config.git_repository_icon {
+        Some(ref git_repository_icon) => git_repository_icon,
+        None => "fa-github",
+    };
+    data.insert("git_repository_icon".to_owned(), json!(git_repository_icon));
 
     let mut chapters = vec![];
 

src/theme/index.hbs

@@ -113,9 +113,9 @@
                             <a href="{{ path_to_root }}print.html" title="Print this book" aria-label="Print this book">
                                 <i id="print-button" class="fa fa-print"></i>
                             </a>
-                            {{#if git-repository-url}}
+                            {{#if git_repository_url}}
-                            <a href="{{git-repository-url}}" title="Git repository" aria-label="Git repository">
+                            <a href="{{git_repository_url}}" title="Git repository" aria-label="Git repository">
-                                <i id="github-button" class="fa fa-git"></i>
+                                <i id="git-repository-button" class="fa {{git_repository_icon}}"></i>
                             </a>
                             {{/if}}
                         </div>