added support for username:password

Signed-off-by: Richard Jones <richard@dagger.io>

stdlib/europa/dagger/engine/git.cue

@@ -11,12 +11,21 @@ package engine
 }
 
 // Pull a directory from a git remote
+// Note: do not add credentials to the remote url: e.g: https://username:password@github.com
+// as this will expose those in logs. By using username and password (as #Secret) Dagger will
+// url encode them for you
 #GitPull: {
 	$dagger: task: _name: "GitPull"
-	remote:      string
-	ref:         string
-	authToken?:  #Secret
-	authHeader?: #Secret
-	keepGitDir:  true | *false
-	output:      #FS
+	remote:     string
+	ref:        string
+	keepGitDir: true | *false
+	{
+		username: string
+		password: #Secret // can be password or personal access token
+	} | {
+		authToken: #Secret
+	} | {
+		authHeader: #Secret
+	}
+	output: #FS
 }