Merge pull request #865 from ugifractal/fix-example-for-custom-render

fix example README for custom render, fix example code for custom render

Author: erickok

example/README.md

@@ -158,6 +158,7 @@ const htmlData = """
       body: SingleChildScrollView(
         child: Html(
           data: htmlData,
+          tagsList: Html.tags..addAll(["flutter"]),
           //Optional parameters:
           style: {
             "html": Style(

example/lib/main.dart

@@ -250,6 +250,7 @@ class _MyHomePageState extends State<MyHomePage> {
       body: SingleChildScrollView(
         child: Html(
           data: htmlData,
+          tagsList: Html.tags..addAll(["bird", "flutter"]),
           style: {
             "table": Style(
               backgroundColor: Color.fromARGB(0x50, 0xee, 0xee, 0xee),