Update docusaurus monorepo to v2.4.0

Author: renovate[bot]

yarn.lock

@@ -1349,9 +1349,7 @@
     tslib "^2.1.0"
 
 "@docusaurus/preset-classic@^2.0.0-alpha.60":
-  version "2.0.0-alpha.73"
-  resolved "https://registry.yarnpkg.com/@docusaurus/preset-classic/-/preset-classic-2.0.0-alpha.73.tgz#f232fd603d35807cf8847bb9bab22cfa0cd6d239"
-  integrity sha512-eXgwPVMXA9K9FmGrXwOeec9Uqr0KXMdHvx3C5Ocm4E7b/mylMGwykOgR9iaSLYdVY12EKrO7T9Lm3Z37Gll7Zw==
+  version "2.4.0"
   dependencies:
     "@docusaurus/core" "2.0.0-alpha.73"
     "@docusaurus/plugin-content-blog" "2.0.0-alpha.73"