Add backup script, README and LICENSE

Read config from config file

run_backup

@@ -0,0 +1,44 @@
+#!/usr/bin/python3
+"""Download CSV of flights from OpenFlights."""
+
+import configparser
+import os.path
+
+from playwright.sync_api import Playwright, sync_playwright
+
+config_file_path = os.path.expanduser(
+    os.path.join(os.getenv("XDG_CONFIG_HOME", "~/.config"), "OpenFlights", "config")
+)
+
+config = configparser.ConfigParser()
+
+config.read(os.path.expanduser(config_file_path))
+
+backup_dir = os.path.expanduser(config.get("backup", "backup_dir"))
+username = config.get("backup", "username")
+password = config.get("backup", "password")
+
+
+def run(playwright: Playwright) -> None:
+    """Run backup."""
+    browser = playwright.chromium.launch(headless=True)
+    context = browser.new_context()
+    page = context.new_page()
+    page.goto("https://openflights.org/")
+    page.locator('input[name="name"]').fill(username)
+    page.locator('input[name="pw"]').fill(password)
+    page.get_by_role("button", name="Log in").click()
+    page.get_by_role("button", name="Settings").click()
+    with page.expect_download() as download_info:
+        page.get_by_role("button", name="Backup to CSV").click()
+    download = download_info.value
+    download.save_as(os.path.join(backup_dir, download.suggested_filename))
+    page.close()
+
+    context.storage_state(path="auth.json")
+    context.close()
+    browser.close()
+
+
+with sync_playwright() as playwright:
+    run(playwright)