[BUG] No mention of 'install elastic docs' under the Knowledge base tab

[muskangulati-qasource]

Documentation links

https://www.elastic.co/docs/solutions/security/ai/ai-assistant-knowledge-base

Description

Which documentation set(s) does this bug apply to?

ESS only

Release version

This bug applies to Elastic Stack 8.18.0 and above releases

Testing environment

Build deployed from the production cloud environment: https://cloud.elastic.co/

[muskangulati-qasource]

@arvindersingh-qasource please review!

[arvindersingh-qasource]

Reviewed and Assigned to @jmikell821