for the community.apigee.com this comes out of the box with the platform we use.
I totally see how this would be a great feature on the dev portal. You should suggest it as an idea as our product team takes into consideration user suggestions when building out a roadmap: https://community.apigee.com/content/idea/post.html?space=15
Hello there, Yes this is a useful feature indeed. To Birute’s point , we are considering integrations with / having easy plug ins with forums or Q&A type software that already has these capabilities for the next iteration of dev portal.