Create gesture demo

Use the Tom's Diner linear gesture example

task id: voxbox-linear-gesture-demo

2024-06-15 11:03: Set up some initial boilerplate files for gesture demo #voxbox-linear-gesture-demo #timelog:01:28:37

2024-06-15 11:42: oh boy, lifetimes #voxbox-linear-gesture-demo

2024-06-15 11:51: maybe I should be using vectors here? #voxbox-linear-gesture-demo

2024-06-15 12:03: Trying to rework things so that the linear gesture doesn't need the path upfront #voxbox-linear-gesture-demo

2024-06-15 12:33: Okay taking a break from this. Still running into ownership problems #voxbox-linear-gesture-demo

2024-06-15 13:45: Did some (re)-reading on the lifetimes chapter, and other research #voxbox-linear-gesture-demo #timelog:00:10:30

2024-06-15 13:57: Things seem to build. Now, will it play? #voxbox-linear-gesture-demo #timelog:00:10:29

2024-06-15 14:08: Tempo control #voxbox-linear-gesture-demo #timelog:00:20:38

2024-06-15 14:30: Some initial write-ups #voxbox-linear-gesture-demo #timelog:00:19:01