6715 improve documentation for dbt clean options

[asarraf]

What are you changing in this pull request and why?

This change is for addressing the issue: #6715

It will help understand the flags for dbt clean command:

• --clean-project-files-only (default)
• --no-clean-project-files-only

Checklist:

1. Enhance the documentation for dbt clean
2. Link the above enhanced documentation in the Upgrading to v1.7 page

NOTE: Requires reviewing the change in the content.

Checklist

• I have reviewed the Content style guide so my content adheres to these guidelines.
• I have added checklist item(s) to this list for anything anything that needs to happen before this PR is merged, such as "needs technical review" or "change base branch."

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Name	Status	Preview	Updated (UTC)
docs-getdbt-com	❌ Failed (Inspect)		Dec 24, 2024 9:44pm

[runleonarun]

This look great! Thank you for contributing to our OS repo and docs project.

I made edits to align with our style guide and naming conventions.

We will test it or get a technical review soon!