Configure commonmark extensions in twig extra bundle

README.md

It is actually possible to include and configure commonmark extensions when using the markdown features of Twig Extra Bundle.

The documentation at https://twig.symfony.com/doc/3.x/filters/markdown_to_html.html does not explain how, so let me show it here.

We need to define a tagged service for the extension and we need to specify the configuration.

⚠️ beware, there is no validation of configuration, neither in Twig Extra Bundle nor in Commonmark that receives the configuration. If your configuration is in the wrong place or has typos, it will simply not be taken into account.

config_packages_twig.yaml

twig_extra:
    commonmark:
        external_link:
            open_in_new_window: true
            noopener: external
            noreferrer: external

config_services.yaml

services:
    League\CommonMark\Extension\ExternalLink\ExternalLinkExtension:
        tags: ['twig.markdown.league_extension']