I/O connectors pages loose the navigation

[ddieruf]

When navigating from the connectors listing [https://pulsar.apache.org/docs/next/io-connectors] to an individual connector page [https://pulsar.apache.org/docs/next/io-canal-source#configuration], the left navigation dissappears.

[Anonymitaet]

I've transferred this issue from pulsar-site to pulsar.
For more context, see apache/pulsar-site#236

[github-actions]

The issue had no activity for 30 days, mark with Stale label.

[tisonkun]

This is somewhat intended that we don't add them on the sidebar. Closed.