Update README.md

[wendellpiez]

Committer Notes

This patch goes with usnistgov/metaschema#176 and documents the new feature (pass JSON literal into XSLT for conversion).

Also other updates and corrections.

All Submissions:

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Have you squashed any non-relevant commits and commit messages? [instructions]
• Do all automated CI/CD checks pass?

Changes to Core Features:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your core changes, as applicable?
• Have you included examples of how to use your new feature(s)?
• Have you updated all OSCAL website and readme documentation affected by the changes you made? Changes to the OSCAL website can be made in the docs/content directory of your branch.

[david-waltermire]

Please get the rebase on the latest to fix the build errors.

[david-waltermire]

LGTM. Thanks!

[iMichaela]

Can you please push a small correction to xml/README.md? Line 33 reads: "System Assessment Report (SAR) XML Schema (Draft): Supports the validation of OSCAL XML-based assessment results content" and it should be "System Assessment Results (SAR) XML Schema (Draft): Supports the validation of OSCAL XML-based assessment results content."