feat: add Dedalus Labs (dedaluslabs.ai) integration docs for LLM analytics

[richardsolomou]

Is your feature request related to a problem?

There are no docs for integrating Dedalus Labs with PostHog LLM analytics, making it harder for Dedalus Labs users to get started.

Describe the solution you'd like

Add integration documentation for Dedalus Labs covering setup and configuration for sending LLM analytics data to PostHog.

Describe alternatives you've considered

Users could follow the generic LLM analytics integration docs, but a dedicated Dedalus Labs guide would reduce friction.

Additional context

N/A

[richardsolomou]

Fixed by #54663