Update api.md

[ali-master]

Minor improvement in API doc

[tofumatt]

The instructions to use async/await aren't really appropriate as code comments. They aren't describing the code: they're instructing the developer/reader directly. I'm fine to annotate the promises version a bit more clearly, but let's revert the async/await change 😄

[ali-master]

Thanks for replying.

If you copy the Async/Await API doc with Or, use `async`/`await`: line, Javascript will throw a syntax error in this line, So It would be better if we comment this line to prevent getting an error.

I saw that mistake when our colleagues copied those lines to use. But finally, if you think it's not so good, I will revert.

[ali-master]

Any news?

[tofumatt]

As those aren't code comments, I'd prefer they be outside the code. Generally only code inside code blocks should be treated as being able to be copied 😄

[ali-master]

I've uncommented that line. Check it again, please