Append message to talk page in
The behaviour of put (which is actually deprecated) is not
to append a message to a page, but to replace it.
This results in replacing the entire talk page with the WLM message,
removing all other messages (like the Welcome message)
- Use page.save instead of the deprecated page.put
- Append the message to the current text and save it
- Also rename variable from comment to summary, for consistency