AB#2306 Public image sharing in Google (#358)

* document how to publicly share images in gcloud
* Write disclamer in debugd
* Add disclamer about debug images to contributing file
* Print debug banner on startup
Signed-off-by: Fabian Kammel <fk@edgeless.systems>

cli/internal/cmd/configfetchmeasurements.go

@@ -50,6 +50,10 @@ func configFetchMeasurements(cmd *cobra.Command, fileHandler file.Handler, clien
 		return err
 	}
 
+	if conf.IsImageDebug() {
+		cmd.Println("Configured image does not look like a released production image. Double check image before deploying to production.")
+	}
+
 	if err := flags.updateURLs(conf); err != nil {
 		return err
 	}