Update: Literally a few hours after recording this video, the ability to like answers on Taro web was shipped.
The #1 priority with the Q&A platform is adding notifications. Here are some important ones:
Being notified when someone answers a question that you have asked
Being notified when someone likes an answer that you have shared, as you should be able to feel good if you have shared your wisdom in a high-quality answer
Overall strategy: Make the process of asking a question and getting answers delightful and silky smooth, as you can't have answers without questions. From there, make it a great experience and rewarding to answer questions.
The ability to write a private "Thank You" note to someone who left a really great answer on your question.
Question askers can choose and highlight an answer on each of their questions, which helped them the most. This is another way to let question answerers know the impact they're having.