Clarification of inner closures

[bmeck]

Inner closures like the direct eval example in the README seem to need some extra clarification. Particularly I would expect:

function foo() {
  const bar = () => this;
}

foo.thisArgumentExpected to equal true since the this comes from the foo environment record specifying that it does have a this binding per HasThisBinding and bar resolving a reference to that statically.

[hax]

@bmeck Thank you for the suggestion, I add a new section for some complex examples, is that ok?

[bmeck]

Yes, thanks