Updated Making OpenSeadragon Plugins (markdown)

Making-OpenSeadragon-Plugins.md

@@ -8,12 +8,13 @@ Tips:
 * If you want to add methods to any of OpenSeadragon's classes, add it to the class's prototype, such as `OpenSeadragon.Viewer.prototype.myFunc = function() { ... }`.
 * Minimize your plugin's footprint: instead of adding a bunch of new methods, just add a single multi-purpose method. That way you're less likely to collide with other plugins, and it'll be easier for developers to keep track of what belongs to your plugin.
 * Use an "options" object in your method to keep things flexible.
+* Perhaps we should have a convention that the plugin file be prefixed with `openseadragon-`, like `openseadragon-scalebar.js`.
 
 Example:
 
 ```
 (function($) {
-  OpenSeadragon.myPlugin = function(options) {
+  $.myPlugin = function(options) {
     options = options || {};
     if (options.foo) {
       ...