Update prerequisites for preview.sh: corepack is required (#845)

* Update prerequisites for preview.sh: corepack is required

* Address review comments

contribute/document-preview.md

@@ -17,10 +17,17 @@ Pulsar documentation is built using [Docusaurus](https://docusaurus.io/). To pre
 
 To verify docs are built correctly before submitting a contribution, you should set up your local environment to build and display the docs locally.
 
-* Node >= 16.14
-* Yarn >= 1.5
+* Node >= 20.0.0 (latest LTS recommended)
+* Corepack enabled (`corepack enable`)
 * Although you can use Linux, macOS, or Windows to build locally the Pulsar documentation, macOS is the preferred build environment as it offers the most complete support for documentation building.
 
+Installing prerequisites with [homebrew](https://brew.sh/) on MacOS or Linux:
+
+```shell
+brew install node
+corepack enable
+```
+
 ### Preview changes
 
 Pulsar website changes refer to all the changes made to the Pulsar website, including but not limited to the following pages: