Fixing Markdown module setup after an upgrade to Drupal 9-compatible 3.x branch


Don’t remember what the deal with this was, saw it at some point clearly,

[08-Mar-2022 12:11:17] WARNING: [pool www] child 19770 said into stderr: “NOTICE: PHP message: Uncaught PHP Exception Drupal\markdown\Exception\MissingVersionException: “The library “commonmark” did not not specify a version. If the plugin has no version, it must be explicitly set to “0.0.0”.” at /var/www/html/web/modules/contrib/markdown/src/Plugin/Markdown/InstallablePluginBase.php line 316”