[Schema] Clarify that not required -> optional
MODIFY
versions/3.0.md
versions/3.0.md
@@ -175,6 +175,8 @@ Relative references used in $ref are processed as per [JSON Reference](https://t
### Schema
+In the following description, if an object is not explicitly **Required** or described with a MUST or SHALL, it can be considered OPTIONAL.
+
#### <a name="oasObject"></a>OpenAPI Object
This is the root document object for the API specification.

[Schema] Clarify that not required -> optional

Signed-off-by: Rob Dolin <robdolin@microsoft.com>