feat: render image in background

app/assets/app.css

@@ -0,0 +1,20 @@
+@font-face {
+  font-family: "Nintendo DS BIOS";
+  src: url("/assets/Nintendo-DS-BIOS.ttf") format("truetype");
+  font-weight: normal;
+  font-style: normal;
+}
+
+* {
+  box-sizing: border-box;
+  margin: 0;
+  padding: 0;
+}
+
+body {
+  font-family: "Nintendo DS BIOS", monospace;
+  -webkit-font-smoothing: none;
+  -moz-osx-font-smoothing: grayscale;
+  image-rendering: pixelated;
+  image-rendering: crisp-edges;
+}