Feature request: update if different

[daeh]

Thanks for the great package, it has been extremely useful.

One feature I'd appreciate is to be able to sync osf with a local folder without overwriting every file. My current solution is to download the repo, diff it with the local directory, and then upload the changed files (and delete the removed files/folders). That works just fine but it'd be great if there was a conflicts="sync" option that did that internally.

I'm imagining that osfr could download files to a temp folder, hash the files, and then overwrite the osf files that have been modified (and delete the osf files/folders that are not present in the local directory).