Docusarus: Init Project (#1312)

Summary:
Pull Request resolved: https://github.com/facebook/yoga/pull/1312

This starts us transitioning the Yoga website off of an ancient version of Gatsby by initializing a new Docusaurus project. This commit adds a new stock project, to be filled in later, then fixes license lint errors.

Note that this seems to have init'd using npm, but in the next diff I convert this to yarn workspaces anyway.

Reviewed By: yungsters

Differential Revision: D46884434

fbshipit-source-id: 7a0a4dddc144ad2d22cd18a02e8dcb9ff2184489

website-next/blog/authors.yml

@@ -0,0 +1,17 @@
+endi:
+  name: Endilie Yacop Sucipto
+  title: Maintainer of Docusaurus
+  url: https://github.com/endiliey
+  image_url: https://github.com/endiliey.png
+
+yangshun:
+  name: Yangshun Tay
+  title: Front End Engineer @ Facebook
+  url: https://github.com/yangshun
+  image_url: https://github.com/yangshun.png
+
+slorber:
+  name: Sébastien Lorber
+  title: Docusaurus maintainer
+  url: https://sebastienlorber.com
+  image_url: https://github.com/slorber.png