add privacy policy

apparently, this is required for chrome web store

docs/privacy-policy.md

@@ -0,0 +1,23 @@
+# Privacy Policy for Rikaitan Extension
+
+At Ajatt-Tools, we value your privacy and are committed to protecting your
+personal information. This Privacy Policy outlines how we collect, use, and
+disclose your personal information when you use our extension.
+
+## Information We Collect
+
+When you use Rikaitan,
+we do not collect any personal information.
+
+## How We Use Your Information
+
+Personal information is never collected and never sent anywhere.
+
+## How We Share Your Information
+
+We do not sell or rent your personal information to third parties.
+We do not share your personal information with third-party service providers.
+
+## Changes to This Privacy Policy
+
+We may update this Privacy Policy from time to time.