No, the fundamental structure of a "type 2" add-on and a "Connect" add-on are totally different. You could share code in some parts, but they're packaged in totally different ways.
Start at https://developer.atlassian.com/index.html for both types and a general introduction to developing for Atlassian.
As a Jira power user, I was at first doubtful that Trello could benefit my workflow. Jira already uses boards (ones you can customize!), so why would I even need to use Trello?! In this post you will...
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