Create a page for YAML-LD

[gkellogg]

Include some information for people wanting to get started with YAML-LD, or use -LD principles for interpreting their YAML. This can serve as the beginnings of a best practices document, but really is for marketing. It should reference examples in the playground, when it supports YAML-LD (see #788).

Examples can come from the spec, and from the auto-generated examples from JSON-LD 1.1

[westurner]

YAML-LD

• Src: https://github.com/json-ld/yaml-ld
• Web: https://json-ld.github.io/yaml-ld/
• Spec: https://json-ld.github.io/yaml-ld/spec
• Docs > Examples: https://github.com/w3c/json-ld-syntax/tree/main/yaml