Add docs and release notes or carthage installation workaround

carthago delenda est

Author: designatednerd

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## v0.33.0
 - Adds support for Xcode 12 and Swift 5.3. ([#1280](https://github.com/apollographql/apollo-ios/pull/1280))
+- Adds workaround script for Carthage support in Xcode 12. Please see [Carthage-3019](https://github.com/Carthage/Carthage/issues/3019) for details. TL;DR: cd into `[YourProject]/Carthage/Checkouts/apollo-ios/scripts` and then run `./carthage-build-workaround.sh` to actually get Carthage builds that work. (#yolo committed to `main`)
 
 ## v0.32.1
 - Improves invalidation of a `URLSesionClient` to include cancellation of in-flight operations. ([#1376](https://github.com/apollographql/apollo-ios/issues/1376))

docs/shared/carthage-installation-panel.mdx

@@ -18,7 +18,7 @@ Add `github "apollographql/apollo-ios"` to your Cartfile.
 
 <h4>Checkout and build dependencies</h4>
 
-Run `carthage update --platform ios` (or `--platform ios,macos` to build both Mac and iOS). **NOTE:** There's an issue with Carthage that has been causing [some frustration](https://github.com/apollographql/apollo-ios/issues/386) for folks trying to build for watch and tvOS - don't build those targets if you don't need to. 
+Run `carthage update --platform ios` (or `--platform ios,macos` to build both Mac and iOS). **NOTE:** There's an issue with the way Carthage uses Lipo in the Xcode 12 GM, please cd into `[YourProject]/Carthage/Checkouts/apollo-ios/scripts` and then run `./carthage-build-workaround.sh` to actually get Carthage builds that work.
 
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