[Feature] Separate images for mod thumbnail and banner

[mwerle]

Currently only a banner image can be uploaded, which is also used for the Thumbnail.

Generally if uploading a file which looks nice as the Thumbnail it looks bad as the banner, and vice versa. Furthermore, there's no information what size/ration the images should be to look good.

So:

1. Separate images (default to current system if someone only uploads a single image)
2. Provide clear information what a "good" image size should be
3. Prevent the banner from tiling if a suitably-sized/ratio'd banner is uploaded
   3a) Maybe add a per-mod option to tile/scale/centre the banner? Some people might like the tiling and have uploaded a suitable image.

[HebaruSan]

Possibly related to #156.

[DasSkelett]

I have an old branch lying around that solves this by changing the banner to a smaller image to the left of all the links and license/version/... infos, with the same aspect ration as the thumbnails.
There was some smaller issue I had with it and I got carried away by more important bugs, but I should try to rebase it and give it another try.

[DasSkelett]

This is how it looks right now in my branch. I think the thing I still had to change was to vertically center the links & co to match the icons.

[mwerle]

Suggestion along with this: Instead of listing (potentially very long) URLs next to the icons, recognise the target like you do with "Forum Thread" for the website (ie, GitHub). If the target is unkown just say "Repository" or something.

Then it can still be in 2 columns as at present and not waste so much vertical space.
Overall the image still seems to use a lot of space though.

How about using the thumbnail image/size on the mod details page as well? And having a separate "Gallery"page where people can upload a couple of images to showcase their mod? Or would that blow out hosting size too much? Might need to restrict number/size of images and deep-linking, or people will use it instead of imgur!

Eh, I'm old-skool, and an engineer to boot. I prefer information to design/layout so maybe not the best person to contribute to this conversation ;)

[Xinayder]

My suggestion is to add separate fields for mod images and banner. We should specify the max dimensions and ratio, and we could also offer a new field for mod authors to upload screenshots or images for their mod, and just replace the image with a carousel or something similar (kinda like Steam does).

[HebaruSan]

Also possibly related to #165 and #224.