Added volume of a torus (#7294)

* Added volume of a torus

Added function calculation the volume of a torus according to the formula:
V = 2 * pi^2 * R * r^2
where R is the major radius and r is the minor radius of the torus.

* Added test for torus volume

src/test/java/com/thealgorithms/maths/VolumeTest.java

@@ -38,5 +38,8 @@ public class VolumeTest {
 
         /* test pyramid frustum */
         assertEquals(140.0, Volume.volumeFrustumOfPyramid(6, 24, 10));
+
+        /* test torus */
+        assertEquals(39.47841760435743, Volume.volumeTorus(2, 1));
     }
 }