[java/need-for-speed] Update analyzer comment (#2360)

This updates the comment to reflect that there are other comparison
operators (other than `<=`) that could be used and to hint more methods
could be added as needed.

This is for exercism/java-analyzer#216

analyzer-comments/java/need-for-speed/avoid_loops.md

@@ -1,4 +1,4 @@
 # avoid loops
 
-Instead of using a loop, consider returning a single expression using the `<=` operator.
-You can re-use the other methods already implemented in the class.
+Instead of using a loop, consider using a single expression based on one of the comparison operators (i.e. `<=`, `>=`, `<`, `>`, etc.). 
+You can re-use the other methods already implemented in the class or add new ones as needed.