feat: add ft_isalpha function

Makefile

@@ -10,7 +10,7 @@ OBJ 	= $(SRC:.c=.o)
 CFLAGS	= -Wall -Wextra -Werror -pedantic
 
 $(LIB): $(OBJ) # <--- OBJ will run $.o: %.c pattern
-	$(STATIC) $(LIB) $(OBJ) 
+	$(STATIC) $(LIB) $(OBJ)
 
 %.o: %.c # <--- compile any .c file into its corresponding .o automatically
 	${CC} ${CFLAGS} -c $< -o $@

ft_isalpha.c

@@ -0,0 +1,8 @@
+#include "libft.h"
+
+int	ft_isalpha(const char c)
+{
+	if ((c > 65 && c < 90) || (c > 97 && c < 122))
+		return (1);
+	return (0);
+}

libft.h

@@ -0,0 +1 @@
+int ft_isalpha(const char c);

test.c

@@ -1,4 +0,0 @@
-void	test(void)
-{
-	return ;
-}