Answer the architecture review: emit-only spellings move down, and the tables drop markdown's words

src/markdown/directive-attributes.ts

@@ -3,6 +3,7 @@ import type { VocabularyPair } from '../adf/attribute-vocabulary.ts'
 import { serializeCanonicalJson } from '../canonical-json.ts'
 
 const bareToken = /^[A-Za-z0-9_-]+$/
+const inlineDirectiveOpener = /^:[a-z][A-Za-z0-9]*[[{]/
 
 // spec/flavour.md, Attributes.
 const quotedEscapes = /[&<`|]/g
@@ -11,6 +12,10 @@ export function isBareToken(text: string): boolean {
   return bareToken.test(text)
 }
 
+export function opensInlineDirective(text: string): boolean {
+  return inlineDirectiveOpener.test(text)
+}
+
 export function spellAttributes(pairs: readonly (readonly [string, string])[]): string {
   if (pairs.length === 0) return ''
   const spelled = [...pairs].sort(([left], [right]) => (left < right ? -1 : 1)).map(([key, value]) => `${key}=${value}`)