[Issue]: Move Migrate from Beats to Elastic Agent out of reference

[KOTungseth]

Type of issue

Inaccurate

What documentation page is affected

https://www.elastic.co/docs/reference/fleet/migrate-from-beats-to-elastic-agent

What happened?

Migrate from Beats to Elastic Agent is task/narrative content, not reference. This content should be moved from reference to Manage data.

Additional info

No response