add process for speaker approval

Webcasts are a large part of our lead generation strategy but require assistance from subject matter experts from outside of marketing to pull off. Until now, our process for recruiting a presenter was to just ping them and ask them and they would agree or not agree.

However, we recognize that participating in a webcast takes time and effort on their part, and not every webcast we are asked to do is a good idea to do. To solve for this, I have added a process for recruiting webcast presenters that requires manager approval of work before getting started.