chore(docs): Recommend yarn instead of for cutting doc versions

[Savio-Sou]

Description

Problem*

Cutting a new doc version with:

npm run docusaurus docs:version <new_version_tag>

did not work on my machine, gave the error of:

npm ERR! Lifecycle script `docusaurus` failed with error: 
npm ERR! Error: Missing script: "docusaurus"

To see a list of scripts, run:
  npm run 
npm ERR!   in workspace: [email protected] 
npm ERR!   at location: /Users/s/Dev/noir-lang/noir/docs 
npm ERR! Missing script: docusaurus

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/s/.npm/_logs/2023-10-25T14_01_36_763Z-debug-0.log

Summary*

Using:

yarn docusaurus docs:version <new_version_tag>

instead worked.

Additional Context

Both approaches are recommended on Docusaurus's docs.

PR Checklist*

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.