sources so we can help maintaining

[mfrasca]

hello Author! would you like us to help you maintaining/updating this cheat sheet? you would need to do two things:

• [ ] change the license to one that allows derivative work
• [ ] provide the sources

[benjamintanweihao]

Will do. Please give me a day or two. :)

[mfrasca]

in the end, you have see, I've worked on a different basis. that for the GenServer. I've not even had a look at the other one about Supervisor.