Docusarus: Init Project

Summary:
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.

Differential Revision: D46884434

fbshipit-source-id: 26e2ecba057ae99c4ef878e4cd21c8d21a25c2b5

website-next/.docusaurus/globalData.json

@@ -0,0 +1,83 @@
+{
+  "docusaurus-plugin-content-docs": {
+    "default": {
+      "path": "/docs",
+      "versions": [
+        {
+          "name": "current",
+          "label": "Next",
+          "isLast": true,
+          "path": "/docs",
+          "mainDocId": "intro",
+          "docs": [
+            {
+              "id": "intro",
+              "path": "/docs/intro",
+              "sidebar": "tutorialSidebar"
+            },
+            {
+              "id": "tutorial-basics/congratulations",
+              "path": "/docs/tutorial-basics/congratulations",
+              "sidebar": "tutorialSidebar"
+            },
+            {
+              "id": "tutorial-basics/create-a-blog-post",
+              "path": "/docs/tutorial-basics/create-a-blog-post",
+              "sidebar": "tutorialSidebar"
+            },
+            {
+              "id": "tutorial-basics/create-a-document",
+              "path": "/docs/tutorial-basics/create-a-document",
+              "sidebar": "tutorialSidebar"
+            },
+            {
+              "id": "tutorial-basics/create-a-page",
+              "path": "/docs/tutorial-basics/create-a-page",
+              "sidebar": "tutorialSidebar"
+            },
+            {
+              "id": "tutorial-basics/deploy-your-site",
+              "path": "/docs/tutorial-basics/deploy-your-site",
+              "sidebar": "tutorialSidebar"
+            },
+            {
+              "id": "tutorial-basics/markdown-features",
+              "path": "/docs/tutorial-basics/markdown-features",
+              "sidebar": "tutorialSidebar"
+            },
+            {
+              "id": "tutorial-extras/manage-docs-versions",
+              "path": "/docs/tutorial-extras/manage-docs-versions",
+              "sidebar": "tutorialSidebar"
+            },
+            {
+              "id": "tutorial-extras/translate-your-site",
+              "path": "/docs/tutorial-extras/translate-your-site",
+              "sidebar": "tutorialSidebar"
+            },
+            {
+              "id": "/category/tutorial---basics",
+              "path": "/docs/category/tutorial---basics",
+              "sidebar": "tutorialSidebar"
+            },
+            {
+              "id": "/category/tutorial---extras",
+              "path": "/docs/category/tutorial---extras",
+              "sidebar": "tutorialSidebar"
+            }
+          ],
+          "draftIds": [],
+          "sidebars": {
+            "tutorialSidebar": {
+              "link": {
+                "path": "/docs/intro",
+                "label": "intro"
+              }
+            }
+          }
+        }
+      ],
+      "breadcrumbs": true
+    }
+  }
+}