Support for the manim-slides plugin

[ruippgoncalves]

It would be great if the extension could support previewing slides created with manim-slides directly in the viewer.

Since manim-slides already provides a built-in HTML exporter, it seems like it might be relatively straightforward to detect slide-based scenes and render them using that output.

This would make it much easier to iterate on presentations without leaving the editor.

[liuktc]

I made various presentation using manim-slides and I succesfully used manim-sideview to view the result.
The only problems are that when you execute the command Manim: Render a New Scene you need to manually specify the name of the class that you want to render and the final animation is just a full video.
Of course you can't interact with it, but to quickly see the result of your code it still works great!

[dkgs2000]

I made various presentation using manim-slides and I succesfully used manim-sideview to view the result. The only problems are that when you execute the command Manim: Render a New Scene you need to manually specify the name of the class that you want to render and the final animation is just a full video. Of course you can't interact with it, but to quickly see the result of your code it still works great!

This manual specification of the class name was solved in my PR: #143