examples: add fireworks example (#8358)

examples/fireworks/modules/objects/vector.v

@@ -0,0 +1,28 @@
+module objects
+
+import math
+import rand
+
+pub struct Vector {
+pub mut:
+	x f32
+	y f32
+}
+
+pub fn (a Vector) + (b Vector) Vector {
+	return Vector{a.x + b.x, a.y + b.y}
+}
+
+pub fn (vector Vector) mult(scalar f32) Vector {
+	return Vector{vector.x * scalar, vector.y * scalar}
+}
+
+pub fn random_vector_in_circle() Vector {
+	theta := rand.f32n(2 * math.pi)
+	y := rand.f32()
+
+	return {
+		x: f32(y * math.sin(theta))
+		y: f32(y * math.cos(theta))
+	}
+}