Replays folder should not be a requirement to a valid osu! directory

[BrettZolstick]

Describe the bug
Hey, I found a minor bug/inconvenience while setting it up for the first time. So Ive actually never saved a replay before (I know, right), and my osu! folder did not have a "Replays" folder. I guess the Replays folder is not created upon installing osu!, but upon exporting a replay. This meant that when I went to select my osu! folder, it would check to see if the selected folder is actually the osu! folder by checking for select files in its contents, but of course it would not find the "Replays" folder because it did not exist. This gave the error message "Does not look like a valid osu! direcory!" I fixed it just by exporting a random replay, which created the file in the osu! directory. Not a big deal at all, just a little inconvenient and unintuitive.

To Reproduce (optional)
Steps to reproduce the behavior:

1. Fresh install of osu! (or just delete the "Replays" folder)
2. Select the osu! directory in Rewind
3. See Error

Expected behavior
Be able to select the osu! folder, even if the Replays folder does not exist, as long as the other files do exist.

Screenshots

Desktop (please complete the following information):

• OS: Windows 10
• Version: 10.0.19043 Build 19043

Additional context
Not sure if this is relevant, but I did copy my entire osu! folder over from a different hard drive a couple weeks ago. Im sure I copied the entire folder, I just have never exported a replay since I first installed osu! BTW, thanks for making this, this is awesome.

[abstrakt8]

Thanks,
I will look into rewriting/relaxing the setup process:

• Reading from osu!.[username].cfg to determine the correct "Songs" folder
• Dropping the requirement of the "Replays" folder

[abstrakt8]

The reason why I want the "Replays" folder to exist is that file watching can not work on folders that do not exist (using chokidar). This means if the user exports a replay for their first time, then Rewind won't be able to detect that new file unless Rewind gets restarted (then it also starts watching on an existing "Replays" folder)

I don't want to create an empty "Replays" folder in the osu! directory because, generally speaking, the only way I want to access the game related files is through reading in order to avoid creating any game breaking issues.