To Clarify the func-style description

[liuchong]

As "foo" is still meaningless, but with "short", we can see that, we are intend to use a short alias name to make our coding happily.

refer to #794

[ljharb]

Sure, thanks

[liuchong]

It's strange that the mark down style breaks, I've check it and found this:

diff README.md README.md.new | cat -A
651c651$
<     const foo = function uniqueMoreDescriptiveLexicalFoo() {$
---$
>  M-BM-  M-BM- const short = function longUniqueMoreDescriptiveLexicalFoo() {$

not sure where it came from, maybe my input software. I was just deleted them an input the blanks again, and it was fixed, sorry about it, this a the new pull request:
#1610

[ljharb]

Thanks