Imports of package configupgrade

PathSynopsis
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
gopkg.in/yaml.v3Package yaml implements YAML support for the Go language.
osPackage os provides a platform-independent interface to operating system functionality.
pathPackage path implements utility routines for manipulating slash-separated paths.
stringsPackage strings implements simple functions to manipulate UTF-8 encoded strings.