Function cargo_auto_lib::auto_plantuml

pub fn auto_plantuml(repo_url: &str)

process plantuml in current directory finds markers (auto_plantuml start) and (auto_plantuml end) in md files if needed calls the web service and saves the svg file Between markers adds the link to the svg file repo_url like https://github.com/bestia-dev/sey_currency_converter_pwa so the image file link is from the repository and accessible everywhere