formatting and renaming subject

subjects/ispowerof2.en.md

@@ -1,19 +1,15 @@
-# ispowerof2
-## Instructions
+## ispowerof2
+
+### Instructions
 
 Write a function that determines if a given number is a power of 2.
 
 This function returns true if the given number is a power of 2, otherwise it returns false.
 
-Your function must be declare as follows:
-
 ## Expected function
 
 ```go
-
-func Ispowerof2(n uint) bool {	
+func Ispowerof2(n uint) bool {
 
 }
-
 ```
-