refactor: migrate from shiki to shikiji (#2520)

composables/tiptap/shikiji-parser.ts

@@ -0,0 +1,20 @@
+import { type Parser, createParser } from 'prosemirror-highlight/shikiji'
+import type { BuiltinLanguage } from 'shikiji/langs'
+
+let parser: Parser | undefined
+
+export const shikijiParser: Parser = (options) => {
+  const lang = options.language ?? 'text'
+
+  // Register the language if it's not yet registered
+  const highlighter = useHighlighter(lang as BuiltinLanguage)
+
+  // If the language is not loaded, we return an empty set of decorations
+  if (!highlighter)
+    return []
+
+  if (!parser)
+    parser = createParser(highlighter)
+
+  return parser(options)
+}