Upgrade to docusaurus v3

[Eomm]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the feature has not already been requested

🚀 Feature Proposal

As titled:

• https://github.com/facebook/docusaurus/releases/tag/v3.0.0
• docs: https://docusaurus.io/docs/migration/v3

Motivation

We need to test the redirects mainly.

Example

[james-kaguru]

@Eomm id like to help out with this issue. I see that Docusaurus required us to update several packages as well as some parts of the code. Should I do it all in one PR or break the updates into several PRs?

[mcollina]

one PR would be best

[james-kaguru]

Well noted @mcollina

[james-kaguru]

Ive seen that one of the files(docx/Reference/TypeScript.md) in the fastify/fastify repo requires an update in order for the project to build. This was identified by running

npx docusaurus-mdx-checker

The command helps with checking for changes that require updates for v3. I will proceed to create a pull request for that.Then come back to address the changes on fastify/website repo.