Android : show www folder in my asset folder when using phonegap

so I'm new at phonegapp and i am having this problem

1. 
   

   i've created a new project

   
   


2. 
   

   i opened the project using android project from existing code

   
   


3. 

inside assets the www folder is not showing the instruction in _where-is-www.txt say :

To show `assets/www` or `res/xml/config.xml`, go to:
Project -> Properties -> Resource -> Resource Filters

And delete the exclusion filter.

but i never found this directory : Project -> Properties -> Resource -> Resource Filters would someone explain to me those instruction and how i can i show the www folder in my asset please