fix: disable golangci-lint gosimple: SA1001 due to false-positive

chore: alleviate shaded variables, update roadmap

fix: updated copyright

fix: upgrade golang-ci-lint to v.1.45.2

feat: added more features to example config file

feat: environment variable expansion in README

fix: improve sample config in README

feat: change read timeout to 2s to prevent abuse

feat: built proper error structs for config validation errors

fix: references to containr version