/topics/pubsub.md has very old, broken example.

[stockholmux]

In pre-publishing review (#91), I noticed that there is a linked example that probably does not work.

Programming example
Pieter Noordhuis provided a great example using EventMachine and Valkey to create a multi user high performance web chat.

On the linked gist it says:

# Update 7 Oct 2010:
# - This example does *not* appear to work with Chrome >=6.0. Apparently,
#   the WebSocket protocol implementation in the cramp gem does not work
#   well with Chrome's (newer) WebSocket implementation.

Note, the current version of Chrome is 125.x

[zuiderkwast]

Deleting the "programming example".