Update README.md

Fixed up code alignment in README.md
Remove -[EXPEpect applyMathcer:to]

This method seemed to add unnecessary complication to the calling convention.
Any matcher declared with `_EXPMatcherImplementationBegin` effectively ignores the `to`
value and instead fetches the actual from the instance with `self.actual`.

This commit just uses -[EXPExpect applyMathcer:]` and makes all the matchers use the passed
in `self.actual`.