Add explanation about comments (#22944)

Add the text "Two backslash characters (//) are used to _comment_ the code, for better understandability. Anything after // on a line is ignored while compiling the program" to help new users understand commenting.

guide/english/c/hello-world/index.md

@@ -12,7 +12,7 @@ To write on console you can use the function `printf()` contained in the library
 
  int main(void)
  {
-     //lines starting with this are called comments, so use them to write notes to the reader about your code!
+     printf("hello, world\n");  // lines starting with this (//) are called comments..
 
      //this code prints "Hello World!"
      printf("Hello World!\n"); //<-- the \n character prints a newline after the string  
@@ -20,19 +20,24 @@ To write on console you can use the function `printf()` contained in the library
      return 0;
  }
  ```
+ 
   ## Explanation 
+  
  * The `#include <stdio.h>` is a preprocessor command. This command tells compiler to include the contents of `stdio.h` (standard input and output) file in the program.
  * The `stdio.h` file contains functions such as `scanf()` and `printf()` to take input and display output respectively.
  * If you use `printf()` function without writing `#include <stdio.h>`, the program will not be compiled.
+ * Two backslash characters (//) are used to _comment_ the code, for better understandability. Anything after // on a line is ignored while compiling the program.
  * The execution of a C program starts from the `main()` function.
  * The `printf()` is a library function to send formatted output to the screen. In this program, the `printf()` displays `Hello World!` text on the screen.
  * The `\n` in `printf` creates a new line for the forthcoming text. 
  * The `return 0;` statement is the "Exit status" of the program. In simple terms, program ends with this statement
 
+
  ## Output:
  ```
  >Hello World!
  ```
+ 
  #### More Information
  
  * Conventionally, the first ever program you write is the "hello world" program, be it in any language.