Some documentation

And replace a force unwrap.

Author: helje5

Sources/express/Express.swift

@@ -296,6 +296,13 @@ extension Express: CustomStringConvertible {
 
 }
 
+/**
+ * If the done closure is called w/ arguments, the first one is considered
+ * the error and the second one the result.
+ * 
+ * I.e. to report an error: done(myError)
+ * To report a result:      done(nil, myValue)
+ */
 public typealias ExpressEngine = (
                    _ path:    String,
                    _ options: Any?,

Sources/express/Mustache.swift

@@ -1,9 +1,9 @@
 //
 //  Mustache.swift
-//  Noze.io / Macro
+//  Noze.io / MacroExpress
 //
 //  Created by Helge Heß on 02/06/16.
-//  Copyright © 2016-2024 ZeeZide GmbH. All rights reserved.
+//  Copyright © 2016-2025 ZeeZide GmbH. All rights reserved.
 //
 
 import func fs.readFile
@@ -14,8 +14,8 @@ import Mustache
 
 let mustacheExpress : ExpressEngine = { path, options, done in
   fs.readFile(path, "utf8") { err, str in
-    guard err == nil else {
-      done(err!)
+    if let error = err {
+      done(err)
       return
     }