Add examples for hooks "page:before" and "page:after"

index.js

@@ -12,19 +12,50 @@ module.exports = {
         // For all the hooks, this represent the current generator
 
         // This is called before the book is generated
-        init: function() {
+        "init": function() {
             console.log("init!");
         },
 
         // This is called after the book generation
-        finish: function() {
+        "finish": function() {
             console.log("finish!");
         },
 
-        // This is called for each page of the book
-        // It can be used for modifing page content
-        // It should return the new page
-        page: function(page) {
+        // The following hooks are called for each page of the book
+        // and can be used to change page content (html, data or markdown)
+
+
+        // Before parsing markdown
+        "page:before": function(page) {
+            // page.path is the path to the file
+            // page.content is a string with the file markdown content
+
+            // Example:
+            //page.content = "# Title\n" + page.content;
+
+            return page;
+        },
+
+        // Before html generation
+        "page": function(page) {
+            // page.path is the path to the file
+            // page.content is a list of parsed sections
+
+            // Example:
+            //page.content..unshift({type: "normal", content: "<h1>Title</h1>"})
+
+            return page;
+        },
+
+        // After html generation
+        "page:after": function(page) {
+            // page.path is the path to the file
+            // page.content is a string with the html output
+
+            // Example:
+            //page.content = "<h1>Title</h1>\n" + page.content;
+            // -> This title will be added before the html tag so not visible in the browser
+
             return page;
         }
     }