Adds additional information about the outputs from the export_business_data function for csv.

[CWDamm-Kint]

brief description of changes

I've added a brief description of the csv output files from export_business_data and what they include.

issues addressed

467

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• [x] the PR branch was originally made from the base branch

This box should be checked

• [x] after these changes the docs build locally without error

This box should only be checked you intend to follow through on it (we can do it on our end too)

• [ ] I will cherry-pick all commits in this PR into other branches that should have them after this PR is merged