chore: fix build by using yarn instead of pnpm

src/main/index.ts

@@ -52,6 +52,12 @@ function createWindow(): void {
   }
 }
 
+if (is.dev) {
+  process.env.NODE_ENV = 'development'
+} else {
+  process.env.NODE_ENV = 'production'
+}
+
 // This method will be called when Electron has finished
 // initialization and is ready to create browser windows.
 // Some APIs can only be used after this event occurs.
@@ -196,8 +202,9 @@ if (lastOpenDir) {
   prepareAndSendDir(lastOpenDir)
 }
 
-// Initially setup watcher for 'hello.md'
-setupWatcher(lastFilePath ?? path.resolve(__dirname, '../../../hello.md'))
+if (lastFilePath) {
+  setupWatcher(lastFilePath)
+}
 
 function getFilesRecursive(
   directory: string,