Consider markdown lint on all .md files (spec, schema readme)

[jeremyfiel]

clean up markdown formatting on all *.md files, not only the spec.

[Bellangelo]

Hi @jeremyfiel, I have opened a PR for this #115. Hope it suits our cases.

[lornajane]

See also the PR on the main OpenAPI repo OAI/OpenAPI-Specification#4515

[ralfhandl]

Closed via

• Markdown linting #205