Add error samples

builder_error1.v

@@ -0,0 +1,8 @@
+module main
+
+import color
+
+fn main() {
+	println(color.red.apply('Hello World'))
+	println(color.bold.apply('Hello World'))
+}

builder_error2.v

@@ -0,0 +1,13 @@
+module main
+
+import color
+
+fn main() {
+	p := color.PaintBrush{
+		fg: color.rgb(0, 0, 0)!,
+		bg: color.hex(0xffffff)!,
+		styles: [color.bold, color.underline, color.italic]
+	}
+
+	print(p.apply('Hello World'))
+}