Bump @docusaurus/preset-classic from 2.0.0-alpha.70 to 2.0.0-alpha.71

Bumps [@docusaurus/preset-classic](https://github.com/facebook/docusaurus/tree/HEAD/packages/docusaurus-preset-classic) from 2.0.0-alpha.70 to 2.0.0-alpha.71.
- [Release notes](https://github.com/facebook/docusaurus/releases)
- [Changelog](https://github.com/facebook/docusaurus/blob/master/CHANGELOG-2.x.md)
- [Commits](https://github.com/facebook/docusaurus/commits/v2.0.0-alpha.71/packages/docusaurus-preset-classic)

Signed-off-by: dependabot[bot] <support@github.com>

docs/package.json

@@ -16,7 +16,7 @@
     "@dflex/draggable": "^0.3.2",
     "@docusaurus/core": "2.0.0-alpha.70",
     "@docusaurus/plugin-pwa": "^2.0.0-alpha.70",
-    "@docusaurus/preset-classic": "2.0.0-alpha.70",
+    "@docusaurus/preset-classic": "2.0.0-alpha.71",
     "@docusaurus/theme-live-codeblock": "^2.0.0-alpha.70",
     "@folo/utils": "^0.1.5",
     "@mdx-js/react": "^1.6.21",