Add deprecation notice for camelCase data types

[aj-stein-nist]

Committer Notes

Addresses goal 3/7 for #558.

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 updated all website](https://pages.nist.gov/metaschema) and readme documentation affected by the changes you made? Changes to the website can be made in the website/content directory of your branch.
• Have you written new tests for your core changes, as applicable?
• Have you included examples of how to use your new feature(s)? N/A but will adjust Deprecate legacy datatypes #558 criteria to include additional goal of reviewing examples, checked there are some old examples in repo (in checked samples and website content) using old camelCase style

[Arminta-Jenkins-NIST]

Committer Notes stated this PR addresses goal 3/7; however, I believe this is goal 7/7. Everything looks good.