Present first 5 minutes of slides during GCs

During the GC yesterday, @sytses mentioned that when there are no questions that the same folks (including himself) step in to help fill that question gap. This MR suggests that people have the first 5 minutes of the GC as a presentation. This gives folks hopping onto the call the opportunity to review the slides and ask questions AND gives the presenter the opportunity to highlight the most important takeaway for folks watching.