maint: moved sin and sway scripts to world folder

Assets/Scripts/World/SinMovement.cs

@@ -0,0 +1,20 @@
+using UnityEngine;
+
+public class SinMovement : MonoBehaviour{
+    private float originalY;
+
+    public float speed;
+    public float scale;
+
+    public float offset;
+    
+    void Start(){
+        originalY = transform.position.y;
+        offset += Random.Range(-1, 1);
+    }
+
+    // Update is called once per frame
+    void Update(){
+        transform.position = transform.position.Flatten(null, originalY + Mathf.Sin((Time.time + offset) * speed) * scale, null);
+    }
+}