add --version to --help

Makefile.dev

@@ -41,7 +41,7 @@ release-arch: clean
 gif: build
 	mkdir -p tmp
 	for i in {1..50}; do \
-		./build/margen -w=1920 -h=720 --seed=$$i$$i -o=tmp/image$$i.bmp ; \
+		./build/$(TARGET) -w=1920 -h=720 --seed=$$i$$i -o=tmp/image$$i.bmp ; \
 	done
 	ffmpeg -y -f image2 -framerate 1 -i tmp/image%d.bmp -vf scale=960x360 images/sample.gif
 	rm -rf tmp

README.md

@@ -53,6 +53,7 @@ generate a marble-like pattern bitmap image, blazing fast.
 
 options:
   --help             show this help message and exit
+  -v, --version      print version
   -q, --quiet        do not print to console
   -w, --width        image width (default: 1920)
   -h, --height       image height (default: 1080)

src/args.c

@@ -1,6 +1,7 @@
 #include "args.h"
 #include "config.h"
 #include "rand.h"
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -28,6 +29,7 @@ void print_help(int status_code) {
        "generate a marble-like pattern bitmap image, blazing fast.\n\n"
        "options:\n"
        "  --help             show this help message and exit\n"
+       "  -v, --version      print version\n"
        "  -q, --quiet        do not print to console\n"
        "  -w, --width        image width (default: 1920)\n"
        "  -h, --height       image height (default: 1080)\n"