Really enjoyed the newest code-splitting docs!
I caught a minor spelling error: `interuptive` -> `interruptive`. I decided to indulge the writer in myself, and chose to rephrase some things that I thought could be clearer.
That said, I recognize that many of the changes I'm making are subjective. More than happy to simply fix the typo, but I thought I'd submit this to see if others agree with my phrasing changes.
* Init Code-Splitting docs
* Fix <Route path="/"> to use exact
* Fix code splitting typos
* Fix note formatting on the website
* Minor tweaks
De-emphasize webpack, mention Next and Gatsby
