Minor grammar edit

Not sure whenever you say to read documentations (where? I thought I'm already reading the documentation, do you mean reading the comment?)

There are four kinds of Matryoshka which an IntrospectBlock can return (i’m not sure which four?).

Also I think it's better to first introduce the usage without getting into the implementation details, which can come after for curious readers.

Also it's not obvious that the project directory contains files not included in the XCode project.