feat: ✨ pass down resume to download_folder

[melMass]

Doesn't change the default behaviour but allow for resumable files inside a folder

[mevinbabuc]

This should be good to merge right ?

[melMass]

Indeed I've been using it as the gdown version in a project here: https://github.com/melmass/comfy_mtb

[achadwick]

This alone doesn't change the behaviour enough to make the feature useful to me, sadly :disappointed:

• main() in cli.py needs to pass resume=args.continue_ to download_folder when it calls it.
• I think gdown --continue should additionally skip files that are known to be 100% transferred. This turns out to be good when a folder's download allowance is very limited and/or when connections are likely to be interrupted half-way through

I've tried to address these in #288 in case folks are interested in that.

[melMass]

I don't use the CLI, just the module but I will close this, I don't think they are interested anyway, and it's a 2 line fix