add simple wireguard support

cmd/dkl-local-server/cluster-render-context.go

@@ -60,6 +60,14 @@ func templateFuncs(sslCfg *cfsslconfig.Config) map[string]any {
 
 	return map[string]any{
 		"quote": strconv.Quote,
+		"yaml":  asYaml,
+		"indent": func(s, indent string) string {
+			buf := new(strings.Builder)
+			for _, line := range strings.Split(s, "\n") {
+				buf.WriteString(indent + line + "\n")
+			}
+			return buf.String()
+		},
 
 		"password": func(cluster, name, hashAlg string) (password string, err error) {
 			key := cluster + "/" + name
@@ -203,7 +211,7 @@ func templateFuncs(sslCfg *cfsslconfig.Config) map[string]any {
 	}
 }
 
-func asYaml(v interface{}) (string, error) {
+func asYaml(v any) (string, error) {
 	ba, err := yaml.Marshal(v)
 	if err != nil {
 		return "", err