Be able to tell pdc to not convert some assets

At the moment pdc is automatically converting all supported assets to their playdate fileformat. This is a really neat feature since it make the conversion transparent and painless if you use the SDK functions, you don't have to think about it.

The issue
However when you want to actually load the actual file, this start to be an issue.
That happened to me on a project where I was using a greyscale png to store information I needed at run time.
To avoid the issue I had to remove the png extension when building the game or add it back when I wanted to edit the file, which is not particularly convenient.

It also happened with the following issue: [Resolved] Error opening file in C based on file extension

It would be nice to be able to tell pdc to not convert certain files.
I think this is mainly useful for C projects were we are a bit more likely to want to access the original fileformat.

The solution(s)?
I am not exactly sure what is the best way to specify which file should be converted or not.

Maybe the easiest would be to specify a folder or file where assets don't need to be converted
pdc MyGameSource MyGame.pdx --ignore rawFiles/

We could also have a filename format for it, but I feel this is a bit awkward to load them with this filename in the game.

A third solution would be to have the possibility in a folder to have a file that list all the files to be ignored. Something like pdc-ignore.txt