Allow to disable syncing scroll in side-by-side mode via options

README.md

@@ -110,6 +110,7 @@ simplemde.value("This text will appear in the editor");
 - **tabSize**: If set, customize the tab size. Defaults to `2`.
 - **toolbar**: If set to `false`, hide the toolbar. Defaults to the [array of icons](#toolbar-icons).
 - **toolbarTips**: If set to `false`, disable toolbar button tips. Defaults to `true`.
+- **syncPreviewSideScroll**: If set to `false`, disable syncing scroll in side by side mode. Defaults to `true`.
 
 ```JavaScript
 // Most options demonstrate the non-default behavior

src/js/simplemde.js

@@ -1667,6 +1667,7 @@ SimpleMDE.prototype.createSideBySide = function() {
 		wrapper.parentNode.insertBefore(preview, wrapper.nextSibling);
 	}
 
+	if(this.options.syncPreviewSideScroll === false) return preview;
 	// Syncs scroll  editor -> preview
 	var cScroll = false;
 	var pScroll = false;