Spherical: improve JSDoc (#27848)

* Spherical: improve JSDoc

* Update Spherical.js

* Update Spherical.js

---------

Co-authored-by: Michael Herzog <[email protected]>

src/math/Spherical.js

@@ -1,12 +1,11 @@
+import * as MathUtils from './MathUtils.js';
+
 /**
  * Ref: https://en.wikipedia.org/wiki/Spherical_coordinate_system
  *
- * The polar angle (phi) is measured from the positive y-axis. The positive y-axis is up.
- * The azimuthal angle (theta) is measured from the positive z-axis.
+ * phi (the polar angle) is measured from the positive y-axis. The positive y-axis is up.
+ * theta (the azimuthal angle) is measured from the positive z-axis.
  */
-
-import * as MathUtils from './MathUtils.js';
-
 class Spherical {
 
 	constructor( radius = 1, phi = 0, theta = 0 ) {