Add Fabric Native Component Guide (facebook#4288)

* FNC: Add Fabric Native Component Guide

- new screenshots
- using package

* FNC: CenteredText -> WebView

* Fix: links

* Fix linter issues

* Update images for webview

* fix: image heights matching for ios and android

* Remove package.json and centertext references

* Update intro

* Update android guide

* Update ios guide

* Update native platform

* Remove codenames

* fix text

* Fix linters and sidebar

---------

Co-authored-by: Riccardo Cipolleschi <[email protected]>

Author: blakef

docs/_fabric-native-components.jsx

@@ -0,0 +1,11 @@
+import React from "react";
+import IOSContent from "./fabric-native-components-ios.md";
+import AndroidContent from "./fabric-native-components-android.md";
+
+export function FabricNativeComponentsIOS() {
+  return <IOSContent />;
+}
+
+export function FabricNativeComponentsAndroid() {
+  return <AndroidContent />;
+}

docs/appendix.md

@@ -4,8 +4,8 @@
 
 - **Spec** - TypeScript or Flow code that describes the API for a Turbo Native Module or Fabric Native component. Used by **Codegen** to generate boilerplate code.
 
-- **Turbo Native Modules** - Native libraries that have no User Interface (UI) for the user. Examples would be persistent storage, notifications, network events. These are accessible to your JavaScript application code as functions and objects.
-- **Fabric Native Component** - Native platform views that are available to your application JavaScript code through React Components.
+- **Native Modules** - Native libraries that have no User Interface (UI) for the user. Examples would be persistent storage, notifications, network events. These are accessible to your JavaScript application code as functions and objects.
+- **Native Component** - Native platform views that are available to your application JavaScript code through React Components.
 
 - **Legacy Native Components** - Components which are running on the old React Native architecture.
 - **Legacy Native Modules** - Modules which are running on the old React Native architecture.