Studio Headless Mode (#36)

This PR adds the capaibility to run Stroyteller studio from the command
line, rendering the result to images. This is the basic functionality,
and there are somethings that I am saving for later when we make this a
more fully fledged feature.

Limitations:
- Right now, you cannot do image output resolutions that aren't 2^n.
This is a bug I plan on tackling later.

If you have questions on how the command line works, use the --help
argument.

Let me know what you think!

---------

Co-authored-by: Danny McGee <dannymcgee@gmail.com>

studio/src/main.rs

@@ -1,11 +1,28 @@
 use bevy::{app::Update, window::close_on_esc};
-use studio::{StudioMode, ViewportSize};
+use clap::Parser;
+use studio::{screenshot::ScreenShotPlugin, StudioMode, ViewportSize};
+
+#[derive(Parser)]
+#[command(name = "StorytellerStudio")]
+#[command(author = "The Storyteller Team")]
+#[command(version = "1.0")]
+#[command(about = "Executable for Storyteller Studio.")]
+#[command(propagate_version = true)]
+struct StudioArgs {
+    model: Option<String>,
+    skybox: Option<String>,
+}
 
 fn main() {
+    let args = StudioArgs::parse();
+
+    let model_path = args.model.unwrap_or("Mannequin.gltf".to_string());
+    let skybox_path = args.skybox.unwrap_or("gum_trees_4k".to_string());
+
     // Edit the arguments here to change the default startup scene or skybox
     let mut app = studio::start_internal(
-        "bookcase.gltf",
-        "gum_trees_4k",
+        model_path.as_str(),
+        skybox_path.as_str(),
         "", // ignored for non-WASM
         "Storyteller Studio",
         ViewportSize::default(),
@@ -14,6 +31,7 @@ fn main() {
 
     // Add any additional systems, resources, etc. for local debugging
     app.add_systems(Update, close_on_esc);
+    app.add_plugins(ScreenShotPlugin);
 
     app.run();
 }