Citra save support

Support downloading Citra saves from Dropbox into Checkpoint.

This requires using a 3DSync.ini generated from concreted.github.io/3dsync/ (not compatible with those generated from https://kyraminol.github.io/3DSync/).

Saves using this release will be placed in the Apps/3DSyncU directory in Dropbox, not Apps/3DS Sync.

The application will attempt to find and download Citra saves in Dropbox to the 3DS's Checkpoint directory. To enable, place your entire Citra sdmc directory in your Dropbox's Apps/3DSyncU directory. The final directory structure in Dropbox should look something like:

Apps
|_3DSyncU
  |_sdmc
    |_Nintendo 3DS
      |_...

Citra saves will show up in Checkpoint under each game with the name Citra.

What's Changed

• Citra sync by @concreted in #1
• README and cleanup by @concreted in #2

New Contributors

• @concreted made their first contribution in #1

Full Changelog: https://github.com/concreted/3DSync/commits/citra-sync