Add subsections

[nszoni]

Since the repository is growing, readability became a problem.

We should further split down each section into subsections.

[zsombor-flds]

Awesome idea!

@nszoni let me know if you have other subsections for consideration. I will prepare/execute a major housekeeping.

I've started to add subsections for:

• Advanced Analytics / ML
• Data Governance -> like Catalogs
• Scaling dbt -> perf related
• Visualization
• Security
• dbt Cloud enhancements

Thanks!

[nszoni]

lgtm!