I'm looking to add a new publishing option inside my articles, so if I want to associate an SVG with the article we can add specific code if a parameter is yes or exclude if the same parameter is no.
I think you need to perform two actions.
First you should add a new extra field for your articles. I recommend to use this extension
It allows you to create new fields for articles using Joomla plugins, so the solutions is really clean.
Once you have added a field to indicate the svg file you have to override the com_content article view.
There is plenty information on the internet about how to do that, like:
Hope it helps you.