Carry the fence depth through blockquotes and lists, and split the block spelling from it

src/directive-attributes.ts

@@ -1,8 +1,7 @@
+import type { AttributeKind } from './adf-document.ts'
 import type { JsonValue } from './json-value.ts'
 import { serializeCanonicalJson } from './canonical-json.ts'
 
-export type AttributeKind = 'boolean' | 'json' | 'number' | 'string'
-
 const bareToken = /^[A-Za-z0-9_-]+$/
 
 export function isBareToken(text: string): boolean {