Use hash rocket in the first DSL-like method call

In the rule for writing a DSL-like method call in multiple lines, the first and second example were the same.

I assume hash rocket is used originally in the first example, but when updating hash rocket to JSON style (i.e. `{ foo: 42 }`) in the documents, it was turned into JSON style by mistake.

The first commit fixes it, and the second fixes a tiny typo in passing.