Clarify dbt fusion guide

[jpetey75]

https://docs.lightdash.com/dbt-guides/dbt-fusion-migration#what-is-dbt-fusion

internal slack thread https://lightdash.slack.com/archives/C03MCQ08UKS/p1765232610865619?thread_ts=1765210645.149989&cid=C03MCQ08UKS

We should clarity how Lightdash works alongside fusion

• works with Lightdash CLI
• Lightdash still compiles with dbt Core v1.10+

[linear]

PROD-1169

[lightdash-bot]

This issue was mentioned by a user in slack: https://lightdash.slack.com/archives/C08PW3909TK/p1765552386223729