Fix readme for section tinyMCE 5. (#265)

* replaces the file_browser_callback with  file_picker_callback in readme

Signed-off-by: alicompu <[email protected]>

* Revert "replaces the file_browser_callback with  file_picker_callback in readme"

This reverts commit bab460d.

* replaces the file_browser_callback with  file_picker_callback in readme

Signed-off-by: alicompu <[email protected]>

Author: alicompu

readme.md

@@ -118,7 +118,7 @@ route('elfinder.tinymce5');
 In the TinyMCE init code, add the following line:
 
 ```javascript
-file_browser_callback : elFinderBrowser
+file_picker_callback : elFinderBrowser
 ```
 
 Then add the following function (change the `elfinder_url` to the correct path on your system):