Readme Cleanup

This update simplifies the README presenter. Highlights:

- Use `superflous` CSS class to denote redundant elements in the README, instead of just stripping the elements out.
- Type `***` to toggle superfluous content, thanks to the magical and tiny [mousetrap](https://www.npmjs.org/package/mousetrap).
- Remove the first H1 if it's 60+% similar to package name, using new [similarity](https://www.npmjs.org/package/similarity) package.
- Remove the first H1 if it contains the package name
- Special case for lo-dash
- cheerio is smart about chaining together selectors with no results, so `if el && el.first() && so on` is not necessary.