Add Nathan's generative line art to title slide.

src/slide/s1_title.rs

@@ -52,6 +52,8 @@ impl Slide for Title {
                 ctx_img!(ui.ctx(), "slime1.png"),
                 ctx_img!(ui.ctx(), "raymarching0.png"),
                 ctx_img!(ui.ctx(), "slime0.png"),
+                ctx_img!(ui.ctx(), "line0.png"),
+                ctx_img!(ui.ctx(), "line1.png"),
             ];
         }