Rename the "examples" folder so that it's clear it's for validation purposes

[afrittoli]

The "example" folders contains example of CDEvents, which are designed with the goal of verifying schemas and doing conformance testing for SDKs, rather than being real-life examples for users to adopt.

We should:

• rename examples to "conformance"
• include a README.md in the folder that explains what they are and how they are used

Additionally, as separate issues, we should

• Add a checkbox in the GitHub PR template about updating conformance when updating the schema
• Add a CI check that figures out if conformance was not updated when it should have been
• Update the SDKs to use the conformance folder instead of examples. This can be done as part of the v0.4.x SDK updates