Update github Campaign Request Form

[laneymangan]

"does your campaign have a timeline" is a drop-down, yes/no. We should add a follow-up mandatory question "if yes, what is the timeline/deadline?"

[AnthonyRollins]

@laneymangan @o-ram is there any other questions we want to add?

[o-ram]

@AnthonyRollins Not that we know of right now, but we might come up with further edits once the campaign guide template is finished...up to you if you want to push this change now or hold off in case we soon have additional things to add.

[AnthonyRollins]

@o-ram PR ready for review #570