This is exactly how our post-mortem functions work -- we pre-generate a google doc with a template and we have the ability to copy (in rich text / markdown) the critical timeline.

On the action item section today actions are tied to Github issues and we are working to extend those - namely Jira/ServiceNow. We do already have a few that gives you a quick look at current status, how long the incident took, and open action items which you can filter by labels or severity (e.g. all severe production issues)

The postmortem doc, meeting link and slack channel are all automatically created for every incident