Reintroduce options block to scene file grammar; remove scene block

src/fart.propane

@@ -31,7 +31,6 @@ token lcurly /\{/;
 token lt /</;
 token options;
 token rcurly /\}/;
-token scene;
 token width;
 
 token uint /\d+/ <<
@@ -47,7 +46,7 @@ token number /-?\d+(\.\d+)?/ <<
     }
 >>
 
-Start -> RenderParams Scene;
+Start -> Options? SceneItems;
 
 Background -> background Vector;
 
@@ -56,14 +55,14 @@ Height -> height uint;
 Number -> uint;
 Number -> number;
 
-RenderParams -> ;
-RenderParams -> RenderParam RenderParams;
+Options -> options lcurly OptionsItems rcurly;
 
-RenderParam -> Background;
-RenderParam -> Height;
-RenderParam -> Width;
+OptionsItems -> ;
+OptionsItems -> OptionsItem OptionsItems;
 
-Scene -> scene lcurly SceneItems rcurly;
+OptionsItem -> Background;
+OptionsItem -> Height;
+OptionsItem -> Width;
 
 SceneItems -> ;