Imports of package linter

PathSynopsis
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
github.com/moby/buildkit/frontend/dockerfile/parserThe parser package implements a parser that transforms a raw byte-stream into a low-level Abstract Syntax Tree.
github.com/pkg/errorsPackage errors provides simple error handling primitives.
stringsPackage strings implements simple functions to manipulate UTF-8 encoded strings.