Fix logo in self-hosted variant.

[nbeirne]

I have started to self-host obligator. I found that the logo is broken when using the Dockerfile as provided, with no config able to fix it.

I was able to fix it for my own use, here: main...nbeirne:obligator:fix-logo-svg. I don't think this fix is acceptable for other people, though. I basically just copy the obligator logo into the docker container, at the static path.

I suppose an alternate fix is to fix LogoPng in the config, then use a docker volume for the static assets. I think it would make sense to fix it for people if they just want to pull the docker image without needing extra configuration, though.

I don't mind making attempting to fix it myself, but I do want your opinion as the maintainer on how you would prefer to do so.

[anderspitman]

I'm not opposed to just using the SVG. Are there any potential pitfalls to that approach? Last time I checked some browsers have issues with SVG favicons, but the logo should be fine.

[nbeirne]

I'm not a web developer, so honestly I have no idea. My biggest worry is breaking other people's configurations and your real production setup. I can open my changes a PR if you like