fix https://github.com/microsoft/vscode/issues/105351

src/vs/vscode.d.ts

@@ -3086,6 +3086,8 @@ declare module 'vscode' {
 		 * @param uri Uri of the new file..
 		 * @param options Defines if an existing file should be overwritten or be
 		 * ignored. When overwrite and ignoreIfExists are both set overwrite wins.
+		 * When both are unset and when the file already exists then the edit cannot
+		 * be applied successfully.
 		 * @param metadata Optional metadata for the entry.
 		 */
 		createFile(uri: Uri, options?: { overwrite?: boolean, ignoreIfExists?: boolean }, metadata?: WorkspaceEditEntryMetadata): void;