I'm having trouble with my Unreal Visual Studio 2019 project. I created a new header file, and saved it in the same folder as my other project files. (I didn't add these existing files, they were in the starter project of the video course I'm following). For some reason, the file is not showing in the VS Solution Explorer, and IntelliSense isn't working in the particular file. How do I fix this? Sorry if it's obvious, I'm not an expert at Visual Studio.