src v4

What's Changed

• Major refactor by @kreatoo in #23
• use a makefile by @getchoo in #24
• add nix flake by @getchoo in #25

Main changes

• nyaa3 is now named kpkg and uses different directories.
• nyaastrap is now named kreastrap.
• No compatibility with older versions (nyaa3, nyaa2, etc.) is guaranteed.
• This repository now contains everything required to build Kreato Linux (except kpkg-repo). This is done to make maintenance easier.

Full Changelog: v3.5...v4