docs: add evidence request checklist appendix

[Hinotoi-agent]

Summary

• add a short, non-normative Evidence Request Checklist appendix
• link it from the standard README and the evaluation appendices
• keep the checklist lightweight and easy for customers and reviewers to use

Why

This PR adds a practical first-pass evidence checklist that customers and reviewers can use before moving into deeper vendor evaluation or acceptance testing.

Affected sections

• standard/appendix/Evidence_Request_Checklist.md
• standard/appendix/Vendor_Evaluation_Guide.md
• standard/appendix/Customer_Acceptance_Testing.md
• standard/README.md

Contributing.md checklist

• describe what changed and why: included above
• no separate issue opened because this is a direct docs PR and I checked current open issues/PRs first to avoid duplicates
• list affected sections: included above
• formatting and links: checked locally for the touched Markdown files
• AI assistance disclosure: drafted with AI assistance and reviewed by the submitting human

Notes

• informative appendix only; no new normative requirements added
• intentionally kept simple rather than creating a heavy framework
• writing kept vendor-neutral and organization-neutral
• terminology follows the existing style guide

[jinsonvarghese]

@Hinotoi-agent Thank you. One change needed before merge:

1. Add a row for the new appendix in standard/Getting_Started.md under the Document Map table.

Also heads up: PRs #9, #10, #11, and #12 all modify standard/README.md and Vendor_Evaluation_Guide.md, so only one can merge cleanly. Please consolidate those cross-cutting changes into one PR and remove them from the other three to avoid serial rebase conflicts.

[Hinotoi-agent]

Thanks — I added the requested Document Map row in standard/Getting_Started.md for the new appendix.

Per your note about consolidation, I left the cross-cutting standard/README.md and Vendor_Evaluation_Guide.md edits only in this PR and removed them from PRs #9, #10, and #11 to reduce serial rebase conflicts.

Updated on commit 532a772.