Hi Nikita,
You're right about the concept, but not about the technique.
"Resources" (adapt-contrib-resources) is an extension that is viewed in the drawer. The drawer has room for other extensions. Getting something to show up in the drawer alongside Resources is not as simple as adding more objects to course,json. That's the technique to use when you are adding more items to Resources. And that is the technique because that's how Resources has been coded. The drawer has not been coded so that it simply consumes text from course.json. The drawer is looking for some plug-in, module, extension, etc., to decide what to display and how to display it. Perhaps below Resources you want an RSS feed. And below that an image gallery. Catch the vision?
If you'd like to have an additional section that looks and operates just like Resources but has different text labels, you can copy adapt-contrib-resources, modify the name wherever it appears, and install it alongside Resources.
That's what I did with adapt-aboutUs. Except that I also made some minor modifications for my purposes. I haven't done everything I want with this extension, but it works. You can install aboutUs to see how it works (be sure to read the README before installation). Comparing it with adapt-contrib-resources might help you locate the code that needs to change. I hope this will encourage you to jump in and play with the code.
Cheers!
Chuck