Update api.md

docs/api.md

@@ -59,7 +59,19 @@ The messageData object will be converted to JSON and passed as a parsed object t
 
 ### events
 * `formulaRender`
-    * Called when a formula is sent to the renderer
+    * Called before a LaTeX formula is sent to the renderer
     * Event data:
         * `latex` - the LaTeX input, **can be modified**
+* `pageSave`
+    * Called before saving the contents of a page 
+    * Event data:
+        * `content` - the HTML content, **can be modified**
+* `pageLoad`
+    * Called before loading a page 
+    * Event data 
+        * `pageId` - the id of the page to be loaded
+* `pageLoaded`
+    * Called when a page has been loaded and is about to be shown
+    * Event data
+        * `content` - the HTML content, **can be modified**