Add $schema to 2019-09 and 2020-12, update README for draft configuration.#586

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handrews merged 13 commits intojson-schema-org:mainfrom

handrews:dollar-schema

Aug 31, 2022

Commits on Aug 11, 2022

Commits on Aug 12, 2022

Optional tests for no $schema (2019-09+)
handrews
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Commits on Aug 13, 2022

Commits on Aug 15, 2022

Remove accidental duplication
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Commits on Aug 24, 2022