feat: add ft_isprint function

libft.h

@@ -2,7 +2,7 @@
 #define LIBFT_A
 
 /*
-    The isalpha() function tests for
+    The ft_isalpha() function tests for
     any character for which isupper(3) or
     islower(3) is true.
  */
@@ -32,4 +32,11 @@ int ft_isalnum(int c);
  */
 int	ft_isascii(int c);
 
+/*
+    The ft_isprint() function tests for 
+    any printing character, including
+    space (‘ ’).
+*/
+int	ft_isprint(int c);
+
 #endif