Bump @docusaurus/preset-classic from 2.0.0-alpha.70 to 2.0.0-alpha.71 (#10)

Author: dependabot[bot]

package.json

@@ -13,7 +13,7 @@
   },
   "dependencies": {
     "@docusaurus/core": "2.0.0-alpha.70",
-    "@docusaurus/preset-classic": "2.0.0-alpha.70",
+    "@docusaurus/preset-classic": "2.0.0-alpha.71",
     "@mdx-js/react": "^1.6.21",
     "clsx": "^1.1.1",
     "react": "^16.8.4",