Add other platforms that one can learn.

[gateremark]

I bet there are other platforms with certification courses that can be of so much help.
Wish you could add links to the best courses in these platforms to avoid resource overload.

[omarsar]

Thanks for the suggestion, @gateremark. I will keep this issue open if there is more interest in this. For now, we would like to keep the collection focused on Youtube open courses.