Fix: remove main method and fix formatting

Author: AshishKumar1297

src/main/java/com/thealgorithms/maths/NeonNumber.java

@@ -2,6 +2,8 @@
 
 public class NeonNumber {
 
+    private NeonNumber(){
+    }
     /**
      * Check if a number is Neon Number.
      * A neon number is a number where a sum of digits of its square equals the number itself.
@@ -12,6 +14,7 @@ public class NeonNumber {
      * @return true if neon number, else --> false
       */
 
+
     public static boolean isNeon(int number)
     {
         int square = number*number;