react-native-windows library

Summary:
This change adds the template for a RNW module to the existing react-native flipper project.

Basically, the changes in this diff are the product of executing the react-native-windows init for the existing library.

See:
https://microsoft.github.io/react-native-windows/docs/getting-started

https://microsoft.github.io/react-native-windows/docs/native-modules-setup

Notes:
There's some auto-generated module code contained in this change: ReactNativeModule (.h/.cpp)

allow-large-files

Reviewed By: passy

Differential Revision: D36751772

fbshipit-source-id: 41207bedb00ea147883f6d13336ed6c1da4454d7

react-native/react-native-flipper/windows/ExperimentalFeatures.props

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+
+  <!--
+    Application projects contain a file with this name to specify some important settings
+    that will apply globally for the app and *all* native modules the app consumes. These
+    values are set by the app developer. However you can also set them here to test building
+    the library solution without an app.
+  -->
+
+  <PropertyGroup Label="Microsoft.ReactNative Experimental Features">
+    <!--
+      Enables default usage of Hermes.
+      
+      See https://microsoft.github.io/react-native-windows/docs/hermes
+    -->
+    <UseHermes>false</UseHermes>
+
+    <!--
+      Changes compilation to assume use of WinUI 3 instead of System XAML.
+      Requires creation of new project.
+
+      See https://microsoft.github.io/react-native-windows/docs/winui3
+    -->
+    <UseWinUI3>false</UseWinUI3>
+
+    <!--
+      Changes compilation to assume use of Microsoft.ReactNative NuGet packages
+      instead of building the framework from source.
+      Requires creation of new project.
+
+      See https://microsoft.github.io/react-native-windows/docs/nuget
+    -->
+    <UseExperimentalNuget>false</UseExperimentalNuget>
+  
+  </PropertyGroup>
+
+</Project>