updated docs

Configuration.md

@@ -59,6 +59,9 @@ config = {
                              // must be disabled for images
                              // basically this skips object box boundary detection for every n frames
                              // while maintaining in-box detection since objects cannot move that fast
+  warmup: 'face',            // what to use for human.warmup(), can be 'none', 'face', 'full'
+                             // warmup pre-initializes all models for faster inference but can take
+                             // significant time on startup
 
   filter: {
     enabled: true,           // enable image pre-processing filters