updates to docs

[fivetran-reneeli]

Pull Request Are you a current Fivetran customer?

Internal What change(s) does this PR introduce?

as part of effort to standardize and update package docs Did you update the CHANGELOG?

• [x] Yes

Does this PR introduce a breaking change?

• [x] Yes (please provide breaking change details below.)
• [ ] No (please provide an explanation as to how the change is non-breaking below.) No, but a lot of facelift warrants a refresh Did you update the dbt_project.yml files with the version upgrade (please leverage standard semantic versioning)? (In both your main project and integration_tests)
• [x] Yes

Is this PR in response to a previously created Bug or Feature Request

• [ ] Yes, Issue/Feature [link bug/feature number here]
• [x] No

How did you test the PR changes?

• [x] CircleCi
• [x] Local (please provide additional testing details below)

Select which warehouse(s) were used to test the PR

• [x] BigQuery
• [x] Redshift
• [x] Snowflake
• [x] Postgres
• [x] Databricks
• [ ] Other (provide details below)

Provide an emoji that best describes your current mood

:dancer: **Feedback** We are so excited you decided to contribute to the Fivetran community dbt package! We continue to work to improve the packages and would greatly appreciate your [feedback](https://www.surveymonkey.com/r/DQ7K7WW) on our existing dbt packages or what you'd like to see next.

[fivetran-reneeli]

I noticed since the package hasn't been updated recently, the generate columns macro is condensed into one file. Assuming we want to break this out too