Fix variable name mistake in modifying-document

Typo

grammer fixes

Update article.md

typo + add link to relevant chapter

typo

typo "if" --> "it"

Remove redundant 'if' from sentence

missing word

Update task.md

Change link destination

Minor grammatical typo fix

Just remove a strange symbol

fix function signature

The first argument should be for handling a successful result, and the second for error.

Fixed typos and made grammar changes.

improved grammar, removed extra punctuation (the "-"), generally attempted to make things make a little more sense, fixed a couple of typos

o -> on
build-in -> built-in

Smooth over some wording

Update article.md

Update article.md

Update arguments order of `then` in Part 1, 11.6 Promisification

Update article.md