Merge pull request #210 from RomainBelorgey/pkg_doc

Add help on using hub-tool as a library

pkg/README.md

@@ -0,0 +1,38 @@
+# Using tool as lib
+
+You can use this tool as a library to make actions to Docker Hub.
+
+## Examples
+
+### Login
+
+```
+username := toto
+password := pass
+
+hubClient, err := hub.NewClient(
+	hub.WithHubAccount(username),
+	hub.WithPassword(password))
+if err != nil {
+	log.Fatalf("Can't initiate hubClient | %s", err.Error())
+}
+
+//Login to retrieve new token to Hub
+token, _, err := hubClient.Login(username, password, func() (string, error) {
+	return "2FA required, please provide the 6 digit code: ", nil
+})
+if err != nil {
+	log.Fatalf("Can't get token from Docker Hub | %s", err.Error())
+}
+```
+
+After a successfull login, it is quite easy to do any action possible and listed inside `pkg/` directory.
+
+### Removing a tag
+
+```
+err = hubClient.RemoveTag("toto/myrepo", "v1.0.0")
+if err != nil {
+	log.Fatalf("Can't remove tag | %s", err.Error())
+}
+```