Add content anchor link

Author: saowang

_sass/_icons.scss

@@ -55,3 +55,8 @@
 .fa-exclamation-circle:before {
   content: "\f06a";
 }
+
+// content
+.fa-link:before {
+  content: "\f0c1";
+}

_sass/class/markdown-body.scss

@@ -49,6 +49,10 @@
     }
   }
 
+  .anchor {
+    padding-right: 0;
+    margin-left: -15px;
+  }
   .highlight pre,
   pre {
     font-size: $font-size-small;

assets/js/theme.js

@@ -267,6 +267,10 @@ $(".toc ul")
     link.prepend(expand);
   });
 
+$(".markdown-body :header").prepend(function () {
+  return `<a href="#${this.id}" class="anchor"><i class="octicon-link fa fa-link text-blue"></i></a>`;
+});
+
 if ("serviceWorker" in navigator) {
   navigator.serviceWorker.register(`${ui.baseurl}/sw.caches.js`);
 } else {