Update README.md for updating crash report uploads (#5207)

Crashlytics/README.md

@@ -9,33 +9,31 @@ integration test FirebaseCrashlytics:
 
 - At least CocoaPods 1.6.0
 - Install [cocoapods-generate](https://github.com/square/cocoapods-generate)
+- For nanopb and GDT:
+    - `brew install protobuf nanopb-generator`
+    - `easy_install protobuf python`
 
 ### To Develop
 
-- Run `pod gen FirebaseCrashlytics.podspec`
+- Run `Crashlytics/generate_project.sh`
 - `open gen/FirebaseCrashlytics/FirebaseCrashlytics.xcworkspace`
 
-OR these two commands can be combined with
-
-- `pod gen FirebaseCrashlytics.podspec --auto-open --gen-directory="gen" --clean`
-
 You're now in an Xcode workspace generate for building, debugging and
 testing the FirebaseCrashlytics CocoaPod.
 
-### Updating crash report proto
+### Running Unit Tests
+
+Open the generated workspace, choose the FirebaseCrashlytics-Unit-unit scheme and press Command-u.
+
+### Changing crash report uploads (using GDT)
+
+#### Update report proto
+
+If the crash report proto needs to be updated, follow these instructions:
 
-If the crash report proto needs to be updated, follow these instructions -
-- Prerequisite installations:
-    - `gem (update|install) cocoapods cocoapods-generate`
-    - `brew install protobuf nanopb-generator`
-    - `easy_install protobuf python`
 - Update `ProtoSupport/Protos/crashlytics.proto` with the new changes
 - Depending on the type of fields added/removed, also update `ProtoSupport/Protos/crashlytics.options`.
  `CALLBACK` type fields in crashlytics.nanopb.c needs to be changed to `POINTER`
  (through the options file). Known field types that require an entry in crashlytics.options are
  `strings`, `repeated` and `bytes`.
-- Run `generate_project.sh` to update the nanopb .c/.h files.
-
-### Running Unit Tests
-
-Open the generated workspace, choose the FirebaseCrashlytics-Unit-unit scheme and press Command-u.
+- Run `generate_project.sh` to update the nanopb .c/.h files.