Yoga Docs: Rename website-next to website (#1613)

Summary:
Pull Request resolved: https://github.com/facebook/yoga/pull/1613

So that GitHub links to edit a page point to the right place.

This will fail in OSS build until I switch the directory used by Vercel instance, but I am waiting to do that until ready to land, since that would cause other in progress changes to fail when exported.

Reviewed By: joevilches

Differential Revision: D54837857

fbshipit-source-id: 9bec90232dbe3ec8638568685671185d597fcf2d

website/.gitignore

@@ -0,0 +1,17 @@
+# Production
+/build
+
+# Generated files
+.docusaurus
+.cache-loader
+
+# Misc
+.DS_Store
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*