Add README.md to packager directory (#2206)

packager/README.md

@@ -0,0 +1,34 @@
+### Steps to update the moduleNames.js and modulePaths.js
+
+1. Uncomment the code snippet in index.js
+2. Run the app on an Android device/simulator in development mode
+3. Open the App, enable the JavaScript debugger from the debug menu, and open the debugger
+4. Copy the console output starting with `module.exports =` into `packager/moduleNames.js`
+4. Run `node packager/generateModulePaths.js`
+5. Run `eslint --fix packager/module*`
+6. Open modulePaths.js
+7. Remove entries for files that don't need to exist on app load:
+	- announcement_banner
+	- options_context
+	- remove_markdown
+	- retry_bar_indicator
+	- search_bar
+	- sidebars
+	- swiper
+	- team_icon
+	- prop-types
+	- react-deep-force-update
+	- react-devtools-core
+	- react-native-video
+	- react-native/Libraries/Core/Devtools
+	- react-native/Libraries/Utilities/deepFreezeAndThrowOnMutationInDev
+	- react-native/Libraries/YellowBox
+	- redux-devtools-instrument
+	- remove-redux-devtools
+	- remotedev-utils
+	- socketcluster-client
+	- stacktrace-parser
+8. Change development versions of certain files to production ones:
+	- configureStore.dev.js -> configureStore.prod.js
+	- react/cjs/react.development.js -> react/cjs/react.production.min.js
+	- schedule/cjs/schedule-tracking.development.js -> schedule/cjs/schedule-tracting.production.min.js