Add rfc3339nano go wont correct (#17)

* Add proper RFC3339Nano to replace the std library bugged implementation

Author: Dean Karn

README.md

@@ -1,6 +1,6 @@
 # pkg
 
-![Project status](https://img.shields.io/badge/version-5.8.0-green.svg)
+![Project status](https://img.shields.io/badge/version-5.9.0-green.svg)
 [![Build Status](https://travis-ci.org/go-playground/pkg.svg?branch=master)](https://travis-ci.org/go-playground/pkg)
 [![Coverage Status](https://coveralls.io/repos/github/go-playground/pkg/badge.svg?branch=master)](https://coveralls.io/github/go-playground/pkg?branch=master)
 [![GoDoc](https://godoc.org/github.com/go-playground/pkg?status.svg)](https://pkg.go.dev/mod/github.com/go-playground/pkg/v5)

time/time.go

@@ -0,0 +1,7 @@
+package timeext
+
+const (
+	// RFC3339Nano is a correct replacement to Go's current time.RFC3339Nano which is NOT sortable and
+	// have no intention of fixing https://github.com/golang/go/issues/19635; this format fixes that.
+	RFC3339Nano = "2006-01-02T15:04:05.000000000Z07:00"
+)