Add support for Reference-style Links

[luisorbaiceta]

Prerequisites

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

🚀 Feature Proposal

Improve remapLinks method to support markdowns Reference-style Links conversion.

The problem has anything to do with the renderer, after some research I found that marked fully supports this type of links.

Motivation

A docs reorganization (fastify/fastify#3474) is taking place right now, and in order to support every possible scenario when linking for the new docs, this needs to be landed.

[jsumners]

@luisorbaiceta do you have time to point out the locations in the code that need to be changed?

[luisorbaiceta]

I have pointed it in the description. The method that needs to target those links with regex is remapLinks

[jsumners]

https://github.com/fastify/website/blob/944247a26dd331f34bb5dfaf240fdff34badc87f/src/scripts/processReleases.js#L176-L208

[luisorbaiceta]

closed this in #307