Rename ArithmaticOperator.txt to Arithmatic_operator.js

Author: MannyP31

Hackerrank solutions/10 days of js/ArithmaticOperator.txt renamed to Hackerrank solutions/10 days of js/Arithmatic_operator.js

@@ -36,4 +36,4 @@ function main() {
 
     console.log(getArea(length, width));
     console.log(getPerimeter(length, width));
-}
+}