📝 D3b-2196 document connecting to Hosted Airflow

[chris-s-friedman]

also moves first time connection instructions to their own page.

Document Connecting to Hosted Airflow

Add a guide on connecting to the hosted airflow instance and move the first-time setup instructions their own guide because those setup instructions are common to both warehouse and airflow connection setup.

Closes D3B-2196

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality
  to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

I have tested connecting to airflow by following my own instructions

Checklist

Please check all of the items below before merging this pull request. If an
item in the list below does not need to be completed, please indicate the
reason why.

• I ensured that all tables have proper source and ref definitions
• I Defined {{ config(schema=[schema name], tags = [list, of, tags]) }} at
  the start of each script
• I have performed a self-review of my own code
• I have checked my code and corrected any misspellings
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature
  works
• My code follows the style guidelines of this project
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes
• I have committed any related changes to the PR
• Run sqlfluff fix on tables that are created or modified in this PR.

Note that unchecked items are not applicable to this documentation-only pull request

[awarkow]

Just added a few suggestions to fix typos but otherwise looks good!

[Christina-J-Diaz]

I was able to successfully follow all the steps up until this one, where I got an unexpected error. I'm going to ask devops about it, but with that in mind I think it would be cool if we could add a screenshot that shows what this final page should look like!

[awarkow]

Looks good!