Swig support

[rtritto]

Prerequisites

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

🚀 Feature Proposal

Add support for template engine Swig.

https://www.npmjs.com/package/free-swig
https://github.com/freecycle/free-swig

Motivation

No response

Example

No response

[Uzlopak]

The problem with additional template engines is not that we dont want them, but that we dont have the resources to add them pro actively.

So if you want your preferred engine added to @fastify/view you should provide a PR. With unit tests and typings tests.

[multivoltage]

Is this library? https://www.npmjs.com/package/swig
It seems deprecated and last commit was done on 2014.
maybe can it be considered useless to implement it?

[rtritto]

free-swig package is mantained and it's the successor of swig package.