Missing reference for how to override the schema types

[rustyconover]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure it has not already been reported

Fastify version

3.x.x

Plugin version

No response

Node.js version

14.x

Operating system

macOS

Operating system version (i.e. 20.04, 11.3, 10)

latest

Description

There is a missing reference in the comment that documents the FastifySchema type.

Steps to Reproduce

look at the docs.

/**
 * Schemas in Fastify follow the JSON-Schema standard. For this reason
 * we have opted to not ship strict schema based types. Instead we provide
 * an example in our documentation on how to solve this problem. Check it
 * out here:
 */

Expected Behavior

Have a reference to follow.

[mcollina]

cc @Eomm

[Eomm]

Done in #3290