Update update warn link

internal/glance/main.go

@@ -56,8 +56,6 @@ func Main() int {
 
 func serveApp(configPath string) error {
 	exitChannel := make(chan struct{})
-	// the onChange method gets called at most once per 500ms due to debouncing so we shouldn't
-	// need to use atomic.Bool here unless newConfigFromYAML is very slow for some reason
 	hadValidConfigOnStartup := false
 	var stopServer func() error
 
@@ -155,7 +153,8 @@ func serveUpdateNoticeIfConfigLocationNotMigrated(configPath string) bool {
 
 	// TODO: update - add link
 	fmt.Println("!!! WARNING !!!")
-	fmt.Println("The default location of glance.yml in the Docker image has changed starting from v0.7.0, please see <link> for more information.")
+	fmt.Println("The default location of glance.yml in the Docker image has changed starting from v0.7.0.")
+	fmt.Println("Please see https://github.com/glanceapp/glance/blob/main/docs/v0.7.0-upgrade.md for more information.")
 
 	mux := http.NewServeMux()
 	mux.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.FS(staticFS))))