Update go.md

Hi Georgi,

I love this article. I wish people would write more articles like this one to give insight into Go's data structures and memory allocations. The only similar one I've seen so far is [Russ Cox's article](http://research.swtch.com/godata). I have some suggestions that I think would make the article more understandable with regards to the differences between the data structures in the examples.

Feel free to dismiss the PR if you don't like them.

G