Align statement on JSON-YAML round-tripping with OpenAPI specification?

[ralfhandl]

Section "Format" states

In order to preserve the ability to round-trip between YAML and JSON formats, [[YAML|YAML version 1.2]] is RECOMMENDED along with some additional constraints:

• Tags MUST be limited to those allowed by the JSON Schema ruleset.
• Keys used in YAML maps MUST be limited to a scalar string, as defined by the YAML Failsafe schema ruleset.

These paragraphs have been copied from the OpenAPI specification's "Format" section.

With OpenAPI 3.2.0 this has been updated and moved to a separate section "JSON and YAML Compatibility" because the "failsafe schema ruleset" isn't failsafe enough.

Should we align this with the OpenAPI specification?

[baywet]

Hey @ralfhandl
Thanks for suggesting we clean this up before the 1.1 release.
I put together #246 to address it. Let me know what you think!