Update Docusaurus and add lockfile to 43 version

Author: lex111

website/package.json

@@ -7,8 +7,8 @@
     "deploy": "docusaurus deploy"
   },
   "dependencies": {
-    "@docusaurus/core": "^2.0.0-alpha.41",
-    "@docusaurus/preset-classic": "^2.0.0-alpha.41",
+    "@docusaurus/core": "^2.0.0-alpha.43",
+    "@docusaurus/preset-classic": "^2.0.0-alpha.43",
     "classnames": "^2.2.6",
     "react": "^16.10.2",
     "react-dom": "^16.10.2"