Allow to write tool specification in YAML

### Description

Writing specification in order to support custom tools is a wonderful feature the original Nuke provided.
But the json format that is required to do so comes with some limitations that YAML support could help circumvent. The major one is being able to write description that spans over multiple lines without having to escape each newline character.

The original description of the issue on the Nuke repository :

> I propose to add the possibility to write specification files using yaml.
> This is because some help text can be very long and json does not support multiple lines for a string (at least I did not found a way to do it 😞 ).
>
> That feature would ease the process of writing tool specification file as we could easily see the whole description and format it as we like.

I even proposed a [PR](https://github.com/nuke-build/nuke/pull/1259) to support Stryker but it never got merged so ... I can conribute here and hopefully add support for that wonderfull tool.

### Usage Example

_No response_

### Alternative

Keep writing in JSON but doing so manually is not an easy task.

### Could you help with a pull-request?

Yes