Remove specific Docusaurus 2 version from README (#5681)

Author: MikeMcC399

README.md

@@ -12,7 +12,7 @@ Cloud & FAQ found at https://docs.cypress.io.
 
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-Our docs are built using [Docusaurus 2](https://docusaurus.io/).
+Our docs are built using [Docusaurus](https://docusaurus.io/).
 
 ### Installation