Rebase on `schema.fields[].examples`?

[roll]

What Data Package version are you using?

v2

Describe the Issue

Currently, there is field.example which is fine but field.examples might be better as:

• follow the JSON Schema approach - https://www.learnjsonschema.com/2020-12/meta-data/examples/ (e.g. extension authors work both with Json Schemas and Table Schemas and it's confusing that it differs)
• only one example might be not enough for generating good documentation

Technically this change will mean (as usually for changes like this) just replacing example with examples and providing a backward compatability note with a requirement to support example (singular) as well.

Participation

• [x] I am willing to submit a pull request for this issue.

[roll]

Sync with https://github.com/frictionlessdata/datapackage/pull/961