How to include my own library in my d program with dub ?

[Vinod K Chandran via Digitalmars-d-learn]

Hi all,
I just build a skeleton of a Gui library(win32 based) for my own 
purpose. How do i use this in my d programs with dub ? Now, all 
files are located in a folder called "GuiLib".
Side note : Why i started making a gui library instead of 
learning language ?
Answer : By this way, i can learn the language and i will have my 
own gui library. Otherwise, i would have struggle with learning a 
third party library.