Since you have removed the markdown feature, i have to make use of the new Info panels instead.
However, i would like you incorporate the work you have already done to the in Confluence into Jira Cloud. 
https://community.atlassian.com/t5/Confluence-articles/New-Customizable-panels-to-make-your-pages-pop/ba-p/1971812

I really would like to remove the icons and customize them a bit. 
You have it confluence, why not Jira ?