added some privacy related optional env-vars

.env.sample

@@ -68,6 +68,14 @@ ENCRYPTED_BY_DEFAULT=all
 # Set these to keyservers you trust - usually the same as your federation allowlist
 #TRUSTED_KEYSERVERS="trusted_key_servers:\n  - server_name: 'example.com'\n  - server_name: 'example2.com'"
 
+# some optional configs to increase privacy and security
+#REQUIRE_AUTH_FOR_PROFILE_REQUESTS=true
+#LIMIT_PROFILE_REQUESTS_TO_USERS_WHO_SHARE_ROOMS=true
+#DELETE_STALE_DEVICES_AFTER=1y
+#SESSION_LIFETIME=60d
+#TRACK_PUPPETED_USER_IPS=true
+
+
 ## Retention
 
 ALLOWED_LIFETIME_MAX=4w