refactor python to support multiple actions

* executable, license header
* prefer `with open` style to auto-close file handles
* keep hardcoding within __main__

script.py

@@ -1,10 +1,15 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: CC0-1.0
+
 from mako.template import Template
 import json
-import itertools
-import argparse
 
-appTemplate = Template(filename='./spaces.html')
-f = open('libregamingspaces.json')
-spaces=json.load(f)
+def render(spaces, template):
+    appTemplate = Template(filename=template)
+    print(appTemplate.render(s=spaces))
 
-print(appTemplate.render(s=spaces))
+if __name__ == '__main__':
+    with open('libregamingspaces.json') as f:
+        spaces = json.load(f)
+
+    render(spaces, './spaces.html')