A new template type "Q&A" is now available to all communities. This template helps create a database of answers received to important community questions. It works simply: by selecting the template, the user asks a question. Then they receive answers in the comments, and the post author selects the answer that helped them. After that, the comment gets a special "Correct answer" label, and the post gets a green checkmark indicating the question is resolved. You can add the template to any rubric in your community settings. 

You can see what it looks like here