Allow use of drawio plugins

[geiseri]

I cannot seem to find a way to add drawio plugins to my editor. It would be nice to allow the use of these. It is unclear though if these are able to be used with embed or just https://app.diagrams.net though. It seems to say that it cannot be supported by Jira/confluence, so maybe it cannot be. If this is the case you can close the issue as wontfix so its preserved for posterity =)