Help! Small but important question

Hello!

I was just wondering how I could make another category on the main menu of Kodi (where you can choose Movies, Pictures, tvshows,settings etc.)
I have many documentaries and i dont wanna mix them With my Movies or TV shows!

I want a New category calles documentaries and I want ONLY my docs there.

How can i do this? Are there any step by step guides?

I use the Nvidia Shield With Kodi

Thanks! Thanks! And Thanks!