How to create sections in custom module

I have create new app and installed in ERPNext, its is also showing as a module now. But when i create doctypes under that module I can only show that doctype under SETUP, SYSTEM, DOCUMENT, OTHER.
How i can make more module sections like we have in our other modules.
I want to make a section in my custom module like, StudentBatchSection, then show multiple doctypes under it.
How it is possible? please help

Please find link below how it’s structured.

Thanks for help.