fix: improve versioning documentation and add showcase example

[Xavier-Redondo]

Pull Request Template

PR Checklist

• I have run npm test locally and all tests are passing.
• I have added/updated tests for any new behavior.
• I have added/updated documentation for any new behavior.
• If this is a significant change, an issue has already been created where the problem / solution was discussed: [N/A, or add link to issue here]

PR Description

No functional changes at all
This pr has two parts:

• creation of a new example project that showcases how the api versioning works. I need this in order to make sure that any change applied due to ESM update does not break the versioning mechanism.
• improve the current documentation to clearly specify what is required to make it work (previous documentation had an example without deprecated, and it did not clearly specify that deprecated was mandatory). I have slightly updated the examples to have them work.

Out of scope of this PR: Before there was no example with express and there is still no example of express. In fact i have removed the reference to it and a TBD due to our plans with it.

This closes #162

[github-actions]

Dependency Review

The following issues were found:

• ✅ 0 vulnerable package(s)
• ✅ 0 package(s) with incompatible licenses
• ✅ 0 package(s) with invalid SPDX license definitions
• ⚠️ 4 package(s) with unknown licenses.

See the Details below.

License Issues

packages/bautajs-fastify-versioning-example/package.json

Package	Version	License	Issue Type
@axa/bautajs-core	^3.1.0	Null	Unknown License
@axa/bautajs-datasource-rest	^3.1.0	Null	Unknown License
@axa/bautajs-fastify	^3.1.0	Null	Unknown License
fastify	^4.15.0	Null	Unknown License

Denied Licenses: GPL-2.0+, AGPL-3.0-or-later, LGPL-2.0-or-later

Scanned Manifest Files

packages/bautajs-fastify-versioning-example/package.json

• @axa/bautajs-core@^3.1.0
• @axa/bautajs-datasource-rest@^3.1.0
• @axa/bautajs-fastify@^3.1.0
• fastify@^4.15.0

[franher]

LGTM, but please do not commit the changes outside the bautajs-fastify-versioning-example.

Thank you for your contribution :)