added code example to the main README

src/utils/utf8.c

@@ -2,8 +2,8 @@
 #include <stddef.h> // NULL
 #include "utf8.h"
 
-// If this is turned on, this library will assume that the 
-// UTF-8 strings will mainly contain ASCII characters.
+// If this is turned on, these functions will assume
+// the UTF-8 strings will mainly contain ASCII characters.
 #define ASSUME_ASCII 1
 
 /* SYMBOL

src/utils/utf8.h

@@ -1,5 +1,5 @@
-#ifndef XUTF8_H
-#define XUTF8_H
+#ifndef UTF8_H
+#define UTF8_H
 #include <stdint.h> // uint32_t
 int utf8_sequence_from_utf32_codepoint(char *utf8_data, int nbytes, uint32_t utf32_code);
 int utf8_sequence_to_utf32_codepoint(const char *utf8_data, int nbytes, uint32_t *utf32_code);