Add Flatpak build

dist/linux/io.github.fgsfdsfgs.perfect_dark.py

@@ -0,0 +1,15 @@
+#!/usr/bin/python
+import argparse
+import subprocess
+
+parser = argparse.ArgumentParser()
+
+for directory in ["data", "saves", "mods"]:
+    abs_dir = os.path.join(os.environ["XDG_DATA_HOME"], directory
+    if not os.path.isdir(abs_dir):
+        os.makedirs(abs_dir)
+
+xdg_data_home = os.environ["XDG_XATA_HOME"]
+default_args = ["--basedir", f"{xdg_data_home}/data", "--savedir", f"{xdg_data_home}/saves"]
+
+subprocess.run(["pd"] + default_args)