fix 3 typos in #Explanation (#21809)

print() for printf()
Hello World! for Hello, World without the ! 
ans spaces between text           on the screen

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

@@ -23,7 +23,7 @@ To write on console you can use the function `printf()` contained in the library
  * 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.
  * 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 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