Reduce Confusion

Hi

Thx for this awesome tute. As a noob, i appreciate the introduction. Suggestion: in the section on callbacks, you repeatedly go back and forth between blocking and non-blocking. To me, this is very confusing. I'd find it easier to understand if you separated your statements about blocking from your statements about non-blocking, like this:

In the blocking version a and b are both called/invoked (they both have () after them which executes the functions immediately). In the blocking version, there is no explicit relationship between a and b.

In the non-blocking version b is a callback to a. In the non-blocking version you will notice that only a gets invoked, and b is simply passed in to a as an argument. In the non-blocking version it becomes a's job to do what it needs to do and then call b when it is done.

チュートリアルのcallbacksセクションを開き、ブロッキングとノンブロッキングの説明を、このissueで提案されている分離と比較してください。2つのケースが別々に説明されるようにセクションを修正し、その後、callbackの関係と呼び出し動作が引き続き明確であることを確認してください。