fix: number of prepend lines sent to LSP

Author: heyzec

src/commands/showPanel.tsx

@@ -58,7 +58,7 @@ async function handleMessage(
           _.set(info, `["${activeEditor.uri}"].chapter`, message.chapter ?? 1);
           // TODO: message.prepend can be undefined in runtime, investigate
           const nPrependLines = message.prepend
-            ? message.prepend.split("\n").length
+            ? message.prepend.split("\n").length + 2
             : 0;
           _.set(info, `["${activeEditor.uri}"].prepend`, nPrependLines);
           context.globalState.update("info", info);