Update block of code to be highlighted as C (#22588)

guide/english/c/operators/index.md

@@ -47,7 +47,9 @@ title: Operators
      int b = a--; // postfix operator; a = 6, b = 7
      int c = --a; // prefix operator; a = 5, c = 5
      ```
-// C Program to demonstrate the working of arithmetic operators
+ 
+ C Program to demonstrate the working of arithmetic operators
+```C
 #include <stdio.h>
 int main()
 {
@@ -70,7 +72,7 @@ int main()
 
     return 0;
 }
-
+```
 ## 2. Relational Operators
 
 - `==` Equal - true when the two operands are equal