Allow teams to upvote features from the Intercom app

The Intercom integration allows teams to send new ideas to Featurebase. We should also be able to upvote existing Featurebase posts from inside Intercom, so the end user doesn't have to necessarily add their upvotes manually.

Flow:

• End users wants to upvote an existing Featurebase post

• Our team (inside Intercom) adds an upvote to that post without leaving Intercom

• A card gets shared with the end user that tells them their vote has been added along with the link to the Featurebase post