Small cleanups after introducing MVP site (#339)

#### Summary

I noticed when working on #338 that
the README.md has some trailing newlines. My VS Code is set up to remove
these on save. I avoided removing them in that PR to keep it focused, so
I'm following up to to remove them here. I'm also clarifying a couple of
the tasks that I added based on
[this](#338 (comment))
feedback.

#### Testing

CI

#### Please review

@airbnb/swift-styleguide-maintainers

Author: bachand