add a few more things that are missing and mention that I can be contacted

README.md

@@ -59,6 +59,12 @@ account:
 
 to do
 
+Also requires `line_id`.
+
+### Finding `line_id` for a specific railway line
+
+to do
+
 ### Updating a subscription
 
 to do
@@ -68,3 +74,9 @@ to do
 - `user_id` seems to change when all subscriptions are deleted and a new one is added
 - `channel_id` seems to change when all subscriptions are deleted and a new one is added
 - subscriptions have to be deleted before an account can be deleted
+
+## Contact Me
+
+Got Questions? Contact me.
+
+XMPP: [xmpp:erebion@erebion.eu](xmpp:erebion@erebion.eu)