how can I include the graphics.h in my c source code ?
This is a forum about the Atom editor and the Electron framework. It isn’t intended for C help, and the number and experience of the C people around here are going to be weaker than on a dedicated C forum. I recommend trying somewhere like Stack Overflow. When you do find somewhere to ask your question, you should include more detail, such as links to the websites for any libraries you’re using, what the current state of your code is, and what you hope to accomplish.