[Request]: Add BMP / Windows BitMap Support

[2artisans]

I'm a video editor. Oftentimes, I have to use older programs as part of my work - some of them unable to output in any image format other than BMP. I'd like to use Caesium to batch convert these files, but the program doesn't support bitmap images. I'd imagine this wouldn't be a difficult thing to add, considering most windows development toolsets include BMP support already.

[Lymphatus]

Caesium v1 used to support BMP, but I removed it in v2 for a couple of reasons:

• BMP usually can't be compressed any further keeping the file format
• It's a pretty obsolete format that's rarely used

The only thing that makes sense to me is to support BMP in input only to be converted to one of the supported formats. I'll keep this in mind going into v3. Thanks!