Adds a new docs website, built with Gatsby JS, to replace the old Jekyll site. Source code for the new site lives in /www (although markdown and YML data still comes from the legacy /docs folder).
Changes to either markdown or website source code can be previewed on Netlify. The react-js bot should automatically add comments to each PR with preview links. (This preview is generated by running the newly-added yarn build:docs command in the root package.json.)
The majority of the changes in this PR are contained within the new /www directory. However some minor modifications have been made to existing content in the /docs directory:
* Modified frontmatter author block to always be an array
* Small markdown formatting tweaks
* Update 2015-12-16-ismounted-antipattern.md
In case anybody else stumbles across this old blog post, I wanted to submit a patch to help with unhandled rejections.
`#then` and `#catch` each return new Promise instances, so here we actually create two new promises (that aren't assigned). If the argument promise to `#makeCancelable` rejects, the promise created by `#then` will be an unhandled rejection, which in Node 7 will be an uncaught error.
By using the second argument of `#then` to handle rejections instead, we don't need to worry about the runtime finding any unhandled rejections here.
* Style updates
* Add update notice