Uniform example domain for the IRIs of OO-LD schemas throughout all repositories

[LukasOro]

I would like to propose a schema document store at oo-ld.org/schemas that we could either:

• use as example domain
• make a real document store that provides versioned schemas

For the Playground, two sample schemas recide directly on GitHub:

• https://github.com/OO-LD/playground/tree/main/examples
• https://oo-ld.github.io/playground/examples/Thing.schema.json
• https://oo-ld.github.io/playground/examples/Person.schema.json

For now, we could create a schemas repository under https://github.com/OO-LD/schemas that would provide the stored schemas in a similar fashion under https://oo-ld.github.io/playground/schemas/