source

extends: entity
properties:
  - key: url
    type: "string"
    description: "where this was captured from"
  - key: captured_at
    type: "string"
  - key: asset
    type: "string"
    description: "vault path of the captured asset file"
  - key: source_enriched
    type: "boolean"
  - key: schema_version
    type: "number"
  - key: enriched_by
    type: "string"
relations:
  - key: about
    targets: [entity]
    description: "what this source is about"

Edit the yaml block above to change the source schema. Prose here is documentation — the plugin ignores it.