Modifying assets requires rebuilding the assembly to take effect

The `CopyAssets` target from [DissonanceEngine.targets](https://github.com/Mirsario/DissonanceEngine/blob/master/DissonanceEngine.targets?ts=4) doesn't run unless a build occurs, and I haven't found a way to make changes to files from the `Assets` ItemGroup trigger a rebuild, besides making them embedded, but that is completely unacceptable.