Update README.md

Some major edits since all is working now.

Author: rohitkataria-sentryio

README.md

@@ -1,20 +1,52 @@
+## Who am I
+
+This is demo repo is used by Solution Engineers when demo'ing Sentry's [React Native](https://docs.sentry.io/platforms/react-native) SDK's capabilties. 
+
 ## Where do I begin 
 
 Please see [INSTALL.md](./Install.md) to get started with the setup.
 
+## What next
+* If you are ready to demo:
+```
+$git clone <this repo>
+Edit App.js to add your Sentry's react-native's project's DSN key
+$npx @sentry/wizard -i reactNative -p ios android
+```
+### Above will :
+* Launch the [Sentry wizard](https://github.com/getsentry/sentry-wizard) allowing you to link with the correct Sentry react-native project.
+* Create `ios/sentry.properties` and `android/sentry.properties`.
+### Gotcha: 
+At this point, you may get an error like:
+* `TypeError [ERR_INVALID_ARG_TYPE]: The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView. Received undefined
+
+From my test runs I've noted that it is safe to look past this error. A minor issue is that it blocks creation of `ios/sentry.properties`. So simply make a copy of `android/sentry.properties` and put it in `ios/sentry.properties`
+
+```
+cp andoid/sentry.properties ios/sentry.properties
+cd ios
+pod install
+```
+
+### To Launch the Demo apps:
+
+* _iOS  version_: `npx react-native run-ios --configuration Release`
+* _Android version_: `npx react-native run-android --variant Release`
 
 ## Why so many files
 
-Please see [Steps](#what-were-the-steps-again) or go through the [first ten commits](https://github.com/sentry-demos/sentry_react_native/commits/master) (and their git log) messages in chronological order, to see the exact commands that were run, step by step, to get all the autogenertaed files we needed as we kept in mind that "junk" does not belong in an SCM system. 
+Actually, its so not that many :-) . The size of this repo is approx. 1.3MB while the size of the [original react-native](https://github.com/sentry-demos/react-native) is approx 350MB. 
 
-Turns out react-native generates it own [.gitignore file](https://stackoverflow.com/questions/49099131/recommended-gitignore-for-react-native/49099219
-), which is of course part of this repo, so only those [autogenerated files](https://stackoverflow.com/questions/48448426/why-dont-we-gitignore-ios-and-android-in-react-native ) that are required for a baseline setup and the original demo code (files) are part of this repo. So now we are at point, where one can simply clone, make a few edits and like DSN, project name, auth token and be up and running.
+Please see [Steps](#what-were-the-steps-again) or go through the [first ten commits](https://github.com/sentry-demos/sentry_react_native/commits/master) (and their git log) messages in chronological order, to see the exact commands that were run and what files that were autogenerated.
 
+Please know that react-native generates it own [.gitignore file](https://stackoverflow.com/questions/49099131/recommended-gitignore-for-react-native/49099219
+), which is of course part of this repo, so only those [autogenerated files](https://stackoverflow.com/questions/48448426/why-dont-we-gitignore-ios-and-android-in-react-native ) that are required for a baseline setup and the original demo code (files) are part of this repo. 
 
-## Where's the "original" code
+So now we are at point, where one can simply clone, make a few edits and like DSN, project name, auth token and be up and running.
 
-Adam worked on App.js which I took as-is from him. Plus the 2 image files in the assets dir (which are also present in [original react-native repo ]( https://github.com/sentry-demos/react-native/commit/269f58d63426065a4de67a3f22d2e774787cd996)
+## Where's the "original" code
 
+Adam worked on App.js which I took as-is from him. I also got from him the 2 image files in the assets dir (which are also present in [original react-native repo ]( https://github.com/sentry-demos/react-native)
 
 ## What else 
 
@@ -24,14 +56,13 @@ Since the assets are taken from there, and that it has its own App.js, it makes
 
 ### Update
 
-So I took the major files from this working demo viz. package.json, package-lock.json, ios/Podfile, ios/Podfile.lock, because it is these files that make the deliverable self-contained, amongst other changes like DSN and put them on top of [original react-native repo ]( https://github.com/sentry-demos/react-native/commit/269f58d63426065a4de67a3f22d2e774787cd996) , and I am getting comile errors for both ios and android. 
+So I took the major files from this working demo viz. `package.json`, `package-lock.json`, `ios/Podfile`, `ios/Podfile.lock`, because it is such files that make the deliverable self-contained, amongst other changes like DSN. When I put them on top of [original react-native repo ]( https://github.com/sentry-demos/react-native/commit/269f58d63426065a4de67a3f22d2e774787cd996) , I am get comile errors for both ios and android versions. 
 
-At this time, I propose, we use this very repo (sentry_react_native) as the new working demo for RN stuff and forget about making them work on TOP of [original react-native repo ]( https://github.com/sentry-demos/react-native/commit/269f58d63426065a4de67a3f22d2e774787cd996) . That to me is now a hacker's or pure development exercise.
+At this time, I propose, we use this very repo (sentry_react_native) as the new working demo for RN stuff and forget about making them work on TOP of [original react-native repo](https://github.com/sentry-demos/react-native) . That to me is now a hacker's or pure development exercise.
 
 ## What were the steps again
 
-This is just the background steps to get to this repo in this state. You can simply clone and  make minimal changes to DSN key to get up and running. 
-
+This is just the background steps to answer "How did we get here ?" . Below is not needed/related to the demoing this app.
 ```
 npx react-native init sentry_react_native (where sentry_react_native is the project name) This generates the boiler plate code for the RN app
 cd sentry_react_native
@@ -55,10 +86,5 @@ cd ios
 pod install
 cd ..
 ```
-
 Ran git commit along the way and finally pushed to this repo.
 
-
-Launch iOS  simulator: `npx react-native run-ios --configuration Release`
-
-Launch Android: `npx react-native run-android --variant Release`