fix phpdoc of basePath method (#36649)

add $path argument

Author: Mohamad Norouzi

src/Illuminate/Support/Facades/App.php

@@ -15,7 +15,7 @@
  * @method static bool runningInConsole()
  * @method static bool runningUnitTests()
  * @method static bool shouldSkipMiddleware()
- * @method static string basePath()
+ * @method static string basePath(string $path = '')
  * @method static string bootstrapPath(string $path = '')
  * @method static string configPath(string $path = '')
  * @method static string databasePath(string $path = '')