✨ allow using project version in templates

src/newsletter.php

@@ -179,6 +179,12 @@
 					return $dataset[$value];
 				}
 				
+				// constant
+				if($key === "const"){
+					if($value === "version") return Project::version();
+					Error::error(message: "Unknown constant name", data: ["value" => $value]);
+				}
+				
 				// unknown key
 				Error::error(message: "Unknown placeholder key", data: ["key" => $key, "value" => $value]);
 			};