Fix example in plugin README

Henrik Ingo · Henrik Ingo · commit 24e28cc43f56 · 2019-01-02T13:35:27.000+02:00
diff --git a/src/plugins/README.md b/src/plugins/README.md
@@ -437,7 +437,7 @@ Example:
     }, false);
     
     // pluginB
-    document.addEventListener("impress:init", function (event) {
+    document.addEventListener("impress:plugina:init", function (event) {
         // plugin B implementation
     }, false);
 
