Bump @docusaurus/core from 2.0.0-alpha.66 to 2.0.0-alpha.68 (#728)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Tom Brien <tom@byth.co.uk>

docusaurus.config.js

@@ -15,6 +15,7 @@ module.exports = {
       logo: {
         alt: "Home Assistant",
         src: "img/logo-pretty.svg",
+        srcDark: "img/logo-pretty.svg",
       },
       items: [
         {

package.json

@@ -12,8 +12,8 @@
   },
   "dependencies": {
     "by-node-env": "^2.0.1",
-    "@docusaurus/preset-classic": "^2.0.0-alpha.66",
-    "@docusaurus/core": "^2.0.0-alpha.66",
+    "@docusaurus/preset-classic": "^2.0.0-alpha.68",
+    "@docusaurus/core": "^2.0.0-alpha.68",
     "classnames": "^2.2.6",
     "react": "^16.14.0",
     "react-dom": "^16.14.0"