Support procurement officer evaluations in the comparison tool

The exceptions are pretty clearly laid out in the [Section508.gov's Determine ICT Exceptions](https://www.section508.gov/buy/determine-ict-exceptions) page.

It would be useful to include a link to this, if vendors are claiming that the product/service is an exception. It would also be useful to highlight that an ACR can only be done on an existing product/service. The point of an ACR is to influence procurement decisions. Contracting could ask for a conformance report at the end of the contract (and probably should) but that should be distinct from a OPAT and should be focused on the accessibility needs of the client as expressed in the contract.

Some departments also have a grading system that is implemented informally to evaluate the quality of a VPAT. The criteria is contract-specific, but generally its:
A: VPAT 2.0 or higher
B: for the most recent version/release
C: filled out to instructions associated with the VPAT or RFP
D: provides sufficient detail in the notes and comments

Some of this could be highlighted in the comparison tool.

Start with the comparison tool and review the linked Section508.gov Determine ICT Exceptions guidance, then inspect how procurement-related information is currently presented. Done means the tool clearly addresses exceptions, the distinction between existing-product ACRs and contract-end reports, and the contract-specific VPAT evaluation criteria described in the issue.

Written by the indexing model from the issue text.