Allow attaching polls to messages

Hey,

Now that polls exist, it would be great if they could be simply attached to messages instead of being standalone, just like images.

Sometimes I find myself in a situation where I want to send an announcement and a poll along with it, but it requires sending two separate messages. Writing the poll itself might also require some time, making it possible that people look at the announcement, see there is nothing to do at all and switch channel, reducing the chance of getting an answer.

What do you think? Let me know if you have any questions.