Create Site OpenAPI specification

[cgendreau]

See DINA-Web/dina-feedback#34

[cgendreau]

Initial file
40823b5

[cgendreau]

You can render the specifications in HTML from the branch with npx @redocly/cli build-docs schema/natural-history-collection-api.yml --output redoc/index.html (requires node 22)

[cgendreau]

Reduced the number of fields for the initial version ffa84ae