add header file to avoid implicit declaration warning

Makefile

@@ -1,15 +1,9 @@
 include config.mk
 
-static: src/libecrypt.c
+all: src/libecrypt.c
 	$(CC) -c src/libecrypt.c -o src/libecrypt.o
 	ar -rc src/libecrypt.a src/libecrypt.o
 
-shared: src/libecrypt.c
-	$(CC) -c -fpic src/libecrypt.c
-	$(CC) -shared src/libecrypt.o libecrypt.so
-
-install-static: src/libecrypt.a
-	install --mode=0755 src/libecrypt.a $(PREFIX)/lib
-
-install-shared: src/libecrypt.so
-	install --mode=0755 src/libecrypt.so $(PREFIX)/lib
+install: src/libecrypt.a include/libecrypt.h
+	install src/libecrypt.a $(PREFIX)/lib
+	install include/libecrypt.h $(PREFIX)/include

README

@@ -4,6 +4,8 @@ A library which provides a random string generation function.
 
 + Usage
 
+	#include <libecrypt.h>
+
 	int main() {
 		ecrypt(PASSWD_LENGTH);
 	}

include/libecrypt.h

@@ -0,0 +1,6 @@
+#ifndef LIBECRYPT_H_
+#define LIBECRYPT_H_
+
+int ecrypt(PASSWD_LENGTH);
+
+#endif