After renaming zulip topic, post a comment under the old topic pointing to the new topic #1590
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After renaming zulip topic (#1588), post an additional comment under the old (now empty) topic pointing to the newly renamed topic. Fixes #1228.
Alternative to #1589. Although #1589 could potentially still be applied. it would just be somewhat redundant.
cc @Mark-Simulacrum @apiraino