Add tarball target in Makefile for release handy.

Author: xiaohanyu

Makefile

@@ -25,5 +25,12 @@ doc/index.html:
 	cp doc/README.html doc/index.html
 	echo "Documentation published to doc/"
 
+tarball:
+	tar czf oh-my-emacs.tar.gz \
+		--exclude-backups \
+		core el-get modules ome-el-get-recipes \
+		CHANGELOG.org CONTRIBUTING.org custom.el init.el \
+		LICENSE.txt Makefile ome.org ome-publish.org README.org
+
 clean:
 	rm -f *.elc *.aux *.tex *.pdf ome*.el ome*.html doc/*html *~ .ome*.part.org