Update Readme to reference use of local package (#2)

Update Readme to reference use of local package

Author: jenmerritt

.gitignore

@@ -46,6 +46,7 @@ app.*.map.json
 /android/app/profile
 /android/app/release
 
+/ios/Podfile.lock
 
 env.json
 

README.md

@@ -2,9 +2,43 @@
 
 This repository contains Flutter sample code demonstrating the capabilities of ArcGIS Maps SDK for Flutter and how to use them in your own app. This SDK enables development of cross-platform GIS apps for mobile devices running iOS and Android.
 
+## Run the samples using the Beta package of ArcGIS Maps SDK for Flutter
+
+Visit [earlyadopter.esri.com](https://earlyadopter.esri.com/) and download the ArcGIS Maps SDK for Flutter package. Follow the instructions to unpack it.
+
+Clone or download this repository into the same parent directory as the `arcgis_maps_package`. Your file structure should be:
+
+```
+parent_directory
+   |
+   |__ arcgis-maps-sdk-flutter-samples
+   |
+   |__ arcgis_maps_package
+```
+
+Navigate to the `arcgis-maps-sdk-flutter-samples` directory.
+
+```
+cd arcgis-maps-sdk-flutter-samples
+```
+
+Use `flutter pub upgrade` to configure the dependencies.
+
+```
+flutter pub upgrade
+```
+
+Install arcgis_maps_core.
+
+```
+dart run arcgis_maps install
+```
+
+Now you are ready to run the samples app!
+
 ## Running the Samples app
 
-The app can be run on an iOS or Android simulator or device.
+The app can be run on an iOS or Android simulator or device. Note: you will need to configure an API key to take full advantage of the samples in the app. See [Configuring API Keys](#configuring-api-keys).
 
 - Open the flutter project in VSCode
 - Ensure a simulator is running or a device is connected to your development machine 
@@ -26,24 +60,34 @@ Individual samples can also be run on an iOS or Android simulator or device.
 
 ## Configuring API Keys
 
-To fully take advantage of the samples in the app, you will need to generate an API Key.
+To take full advantage of the samples in the app, you will need to generate an API Key.
 
-- Log into your developer account at the [ArcGIS Developers](https://developers.arcgis.com/)
+- Log into your developer account at [ArcGIS Developers](https://developers.arcgis.com/)
   - If you do not have an account, [create one](https://developers.arcgis.com/sign-up/)
 - Go to the "API keys" tab
 - Click the "New API Key" button and provide a Title and Description
 - Set Location Service scopes to add or remove key capabilities
 
-Add the new API Key directly to [main.dart](lib/main.dart) or create an environment JSON file that can be loaded with the `--dart-define-from-file` `flutter run` command line argument. 
+Add the new API Key directly to [main.dart](lib/main.dart) or create an environment JSON file that can be loaded with the `--dart-define-from-file` `flutter run` command line argument.
+
+The JSON file itself should be of the format:
+
+```
+{
+    "API_KEY": "your_api_key_here"
+}
+```
+
+To run using the JSON file to define your API key:
 
 ```
 flutter run --dart-define-from-file=path/to/json/file.json
 ```
 
-or to run an individual sample:
+Or to run an individual sample:
 
 ```
-flutter run  lib/src/samples/display_map.dart --dart-define-from-file=path/to/json/file.json
+flutter run lib/src/samples/display_map.dart --dart-define-from-file=path/to/json/file.json
 ```
 
 ## Licensing

ios/Podfile.lock

@@ -12,7 +12,7 @@ dependencies:
     sdk: flutter
 
   arcgis_maps:
-    path: ../arcgis_maps
+    path: ../arcgis_maps_package
 
   async: ^2.11.0
   path_provider: ^2.1.2