Add Document.save() method

 # 1.3.3
 * Fix a bug with the RichText Widget
 * Update code to Dart 2.1.0
+* Add Document.save() method
 
 # 1.3.2
 * Fix dart lint warnings

@@ -147,5 +147,5 @@ void main() {
           ]));
 
   final File file = File('example.pdf');
-  file.writeAsBytesSync(pdf.document.save());
+  file.writeAsBytesSync(pdf.save());
 }

@@ -41,6 +41,8 @@ class Document {
   void addPage(BasePage page) {
     page.generate(this);
   }
+
+  List<int> save() => document.save();
 }
 
 typedef BuildCallback = Widget Function(Context context);

@@ -85,6 +85,6 @@ void main() {
     }
 
     final File file = File('metrics.pdf');
-    file.writeAsBytesSync(pdf.document.save());
+    file.writeAsBytesSync(pdf.save());
   });
 }

@@ -176,6 +176,6 @@ void main() {
                 ])));
 
     final File file = File('widgets.pdf');
-    file.writeAsBytesSync(pdf.document.save());
+    file.writeAsBytesSync(pdf.save());
   });
 }

 # 1.3.5
 * Restore compatibility with Flutter 1.0.0
 * Update code to Dart 2.1.0
+* Depends on pdf 1.3.3
 
 # 1.3.4
 * Fix iOS build with Swift

@@ -43,7 +43,7 @@ class MyApp extends StatelessWidget {
               )),
             );
           }));
-    return pdf.document.save();
+    return pdf.save();
   }
 }
 ```

@@ -13,7 +13,7 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  pdf: "^1.3.2"
+  pdf: "^1.3.3"
 
 dev_dependencies:
   flutter_test: