fixup! Add first cut of git-credential-fdoss

Add example of git-credential protocol.

Addresses: #3 (comment)

gitcred.go

@@ -15,6 +15,17 @@ import (
 // [git-credential] protocol. It can be unmarshal from an [io.Reader] and
 // marshaled to an [io.Writer].
 //
+// The git-credential protocol is a simple line-based key/value pair text
+// protocol. A simple example for storing a secret is:
+//
+//	protocol=https
+//	host=example.com
+//	username=bob
+//	password=secr3t
+//
+// A similar input without the "password" field would be used to retrieve a
+// secret.
+//
 // [git-credential]: https://git-scm.com/docs/git-credential#IOFMT
 type GitCredential struct {
 	Protocol          string