Add dependency to build instructions for Fedora 36

When I first tried to build using the included instructions (on Fedora 36), CMake failed, complaining about a missing I18n. So, I just looked for packages with similar names that have fitting descriptions. kf5-ki18n-devel was the first one that I tried because the description seemed really promising. CMake immediately was able to continue and Latte Dock finished building and installing successfully. It also functions exactly as expected now.

This small addition to the dependency installation command should reduce the speed bumps for Fedora users.