Add tracker devices;

api/lovr/headset/Device.lua

@@ -21,6 +21,54 @@ return {
       name = 'right',
       description = 'A shorthand for hand/right.'
     },
+    {
+      name = 'elbow/left',
+      description = 'A device tracking the left elbow.'
+    },
+    {
+      name = 'elbow/right',
+      description = 'A device tracking the right elbow.'
+    },
+    {
+      name = 'shoulder/left',
+      description = 'A device tracking the left shoulder.'
+    },
+    {
+      name = 'shoulder/right',
+      description = 'A device tracking the right shoulder.'
+    },
+    {
+      name = 'chest',
+      description = 'A device tracking the chest.'
+    },
+    {
+      name = 'waist',
+      description = 'A device tracking the waist.'
+    },
+    {
+      name = 'knee/left',
+      description = 'A device tracking the left knee.'
+    },
+    {
+      name = 'knee/right',
+      description = 'A device tracking the right knee.'
+    },
+    {
+      name = 'foot/left',
+      description = 'A device tracking the left foot or ankle.'
+    },
+    {
+      name = 'foot/right',
+      description = 'A device tracking the right foot or ankle.'
+    },
+    {
+      name = 'camera',
+      description = 'A device used as a camera in the scene.'
+    },
+    {
+      name = 'keyboard',
+      description = 'A tracked keyboard.'
+    },
     {
       name = 'eye/left',
       description = 'The left eye.'