Add Out of Office coverage issue template

Following up from this question/idea from @nicolasdular (via Slack) to have an OOO coverage issue template:

Do we have something like OOO coverage issues in Conversion/Expansion (now Acquisition)? (especially for PTO longer than a week)
It’s mostly used to make sure everything is set up properly, and communicate about the open work while one is on PTO - if someone else wants / needs to take over.