feat: add hand tracking and painting functionality using ml5.js handPose model

- Implemented hand tracking with real-time video capture
- Added GUI controls for canvas background, keypoints, connections, and hand settings
- Enabled painting with hand gestures, including pinch to draw and clear gesture
- Configured rendering options for keypoints and connections
- Introduced bounds visualization for detected hands

default_cam

@@ -0,0 +1,19 @@
+#!/bin/bash
+# Make default camera /dev/video0 point to the "best" camera present.
+
+if [ -h /dev/video0 ]; then 
+   sudo rm /dev/video0   # not first run: remove our old symlink
+elif [ -e /dev/video0 ]; then
+   sudo mv /dev/video0 /dev/video0.original   # first run: rename original video0
+fi 
+if [ -e /dev/video1 ]; then
+   sudo ln -s /dev/video1 /dev/video0   # symlink to video1 since it exists
+   echo "Set default camera /dev/video0 --> external camera /dev/video1"
+elif [ -e /dev/video0.original ]; then  # symlink to video0.original otherwise
+   sudo ln -s /dev/video0.original /dev/video0
+   echo "Set default camera /dev/video0 --> integrated camera /dev/video0.original"
+else
+   echo "Sorry, does this machine have no camera devices?"
+   ls -l /dev/video*
+fi
+