Link to "easier to understand introduction to JSON Schema" guide is broken on Schema page #166

On the schema documentation page page, the document links to https://spacetelescope.github.io/understanding-json-schema/index.html for the easier to understand schema. That link is no longer valid. It redirects to https://json-schema.org/understanding-json-schema/index.html which is also giving more 404.

The most appropriate current link should be https://json-schema.org/learn/getting-started-step-by-step or we could link to the archive.org latest snapshot from August 2022 https://web.archive.org/web/20220816060920/https://json-schema.org/understanding-json-schema/index.html

What do you think is the suitable replacement? I will be glad to assist with PR if needed.

Thank you