Add resize scale enum variant

[TadoTheMiner]

This pr adds the Resize::Scale option in #59, and adds it to the demo instead of the placeholder. I've noticed that in the code three times static was used when const could be, so I replaced it. As I changed the demo to include the Resize::Scale option, the gif must be re-generated

[benjajaja]

First of all, thank you! I really had const and static mixed up, now I see that.

You can run an approximation of the CI with cargo make ci if you install cargo-make. Or just run clippy.

This is suprising to me, I would expect the image to scale down as well instead of being cropped. I also suspect it's not really getting cropped, just overdrawn, which might cause subtle problems down the line.

Could you look into this? I think for Scale(_), the "desired" area is not just the max(image, container) width and height, but instead the image scaled to always fit container and keeping the aspect ratio.

[TadoTheMiner]

By the way do we really need to have text under the images in the demo?

[benjajaja]

It scales down, but sometimes it doesn't take up the full space if you play around with window size / layout.

By the way do we really need to have text under the images in the demo?

It helps a lot to eyeball glitches in different terminals. Since we're writing control sequences into some buffer, there can and have been conflicts with surrounding control sequences related to style.

[TadoTheMiner]

This is an issue with the library in general as it occurs in Fit aswell. So I think you should open an issue about it, that both fit and scale don't resize properly

[benjajaja]

@TadoTheMiner okay, yea there seems to be some bug, although I can't exactly reproduce your screenshot.

I will merge this branch manually and push to master. I just disabled merge commits while you were working on this, sorry. I'll also add a note to the readme about this.

[benjajaja]

Rebased and merged in main. I'll have to check some general resize related bugs before I make a release.