add: gitman support

gitman_install.sh

@@ -0,0 +1,27 @@
+install() {
+	make -j $(nproc)
+	mv build/zeta "$GITMAN_BIN"/zeta
+	mkdir -p ~/.config/zeta
+	cp -r assets/* ~/.config/zeta/
+	chmod +x ~/.config/zeta/update.sh
+	CURRENT_HASH=$(curl -H "Accept: application/vnd.github+json" \
+        	https://api.github.com/repos/acidicneko/zeta/commits/main \
+        	| grep sha \
+        	| awk 'NR==1{print $2}' \
+        	| sed 's/[",]//g')
+	echo "LAST_HASH=$CURRENT_HASH" > "$HOME"/.config/zeta/last_commit
+}
+
+uninstall() {
+	rm "$GITMAN_BIN"/zeta
+	rm -rf ~/.config/zeta
+}
+
+if [ $1 = "install" ] ; then 
+	install
+elif [ $1 = "uninstall" ] ; then
+	uninstall
+else
+	echo unknown option
+	exit 1
+fi