Adding in the mannequin file and setting it as the default.

studio/src/main.rs

@@ -4,7 +4,7 @@ use studio::{StudioMode, ViewportSize};
 fn main() {
     // Edit the arguments here to change the default startup scene or skybox
     let mut app = studio::start_internal(
-        "sample-room",
+        "Mannequin.gltf",
         "gum_trees_4k",
         "", // ignored for non-WASM
         "Storyteller Studio",

studio/src/scene.rs

@@ -151,7 +151,7 @@ fn init_scene_loading(
 ) {
     if let Some(id) = er.read().last() {
         let name = &**id;
-        let path = format!("gltf/{name}.gltf");
+        let path = format!("gltf/{name}");
 
         // Avoid trying to re-load this scene if it's already active
         if let Some(active_scene_path) =