Move Map Libre API key to Xcode Cloud (#1313)

* Add config_production lane

* Add maplibre to .gitignore

* Add setupMapLibreKey

* Add documentation

* Fix failing UTs

* Fix more UTs

* Cleanup

* Add secrets.xcconfig

* Cleanup gitignore file

* Update post-checkout hook

* Cleanup SetupProject

* Update project

* Remove leftover in SetupProject

* Cleanup project.yml

* Add fastlane-plugin-xcconfig

* Improve test

* Update docs

README.md

@@ -41,6 +41,10 @@ When you are experiencing an issue on ElementX iOS, please first search in [GitH
 and then in [#element-x-ios:matrix.org](https://matrix.to/#/#element-x-ios:matrix.org).
 If after your research you still have a question, ask at [#element-x-ios:matrix.org](https://matrix.to/#/#element-x-ios:matrix.org). Otherwise feel free to create a GitHub issue if you encounter a bug or a crash, by explaining clearly in detail what happened. You can also perform bug reporting (Rageshake) from the Element application by shaking your phone or going to the application settings. This is especially recommended when you encounter a crash.
 
+## Forking
+
+Please read our [forking guide](docs/FORKING.md).
+
 ## Copyright & License
 
 Copyright (c) 2022 New Vector Ltd