Add pdf rendering

lib/sheetview.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:pdfx/pdfx.dart';
 import 'package:sheetless/sheet.dart';
 
 class SheetViewerPage extends StatefulWidget {
@@ -11,13 +12,23 @@ class SheetViewerPage extends StatefulWidget {
 }
 
 class _SheetViewerPageState extends State<SheetViewerPage> {
+  PdfControllerPinch? controller;
+
+  @override
+  void initState() {
+    controller =
+        PdfControllerPinch(document: PdfDocument.openFile(widget.sheet.path));
+    super.initState();
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
-      appBar: AppBar(
-        title: Text(widget.sheet.name),
-      ),
-      body: Center(child: Text(widget.sheet.author)),
-    );
+        appBar: AppBar(
+          title: Text(widget.sheet.name),
+        ),
+        body: PdfViewPinch(
+          controller: controller!,
+        ));
   }
 }