docs(ispowerof2): improve subject

- substitute $ with <sup> tag to be compatible with the platform
- run prettier

subjects/ispowerof2/README.md

@@ -2,9 +2,9 @@
 
 ### Instructions
 
-Write a program that determines if a given number is a power of 2. A number `n` is a power of 2 if it meets the following condition: $n = 2 ^ m$ where m is another integer number.
+Write a program that determines if a given number is a power of 2. A number `n` is a power of 2 if it meets the following condition: **n = 2 <sup>m</sup>** where m is another integer number.
 
-For example, $4 = 2 ^ 2$ or $16 = 2 ^ 4$ are power of 2 numbers while 24 is not.
+For example, **4 = 2 <sup>2</sup>** or **16 = 2 <sup>4</sup>** are power of 2 numbers while 24 is not.
 
 This program must print `true` if the given number is a power of 2, otherwise it has to print `false`.
 
@@ -12,8 +12,6 @@ This program must print `true` if the given number is a power of 2, otherwise it
 
 - When there is only one argument, it will always be a positive valid `int`.
 
-
-
 ### Usage :
 
 ```console