v0.4

This brings v0.4
Most changes are rather small, doing some tweaks here and there.
Bigger changes are to the project structure, the CI workflow and the addition of a small web status page

What's Changed

• Merge v0.4 changes by @simonl169 in #26

Other changes

• Improvements to CI and Release workflow by @simonl169 in #18
• Check wether Updating is neccessary by @simonl169 in #19
• Add a check if an update is necessary by @simonl169 in #21

Full Changelog: https://github.com/simonl169/dns-owl/compare/v0.3.1...