feat(language-server): add tag folding and linked editing

packages/language-server/src/html-service.ts

@@ -77,6 +77,22 @@ export function htmlFoldingRanges(
     .map((range) => ({ startLine: range.startLine, endLine: range.endLine }));
 }
 
+/** Ranges of the opening and closing tag names, so renaming one renames both. */
+export function htmlLinkedEditingRanges(
+  document: TextDocument,
+  position: Position,
+): Array<{ start: Position; end: Position }> | null {
+  if (!isInsideHtml(document, offsetAt(document.text, position))) return null;
+
+  const virtual = htmlDocument(document);
+  const ranges = service.findLinkedEditingRanges(
+    virtual,
+    position,
+    service.parseHTMLDocument(virtual),
+  );
+  return ranges && ranges.length ? ranges : null;
+}
+
 /**
  * Detects `<Name attr="x" /` just before `position` and completes the `>`.
  *