doc: add about arch filter

README.md

@@ -71,12 +71,17 @@ The Testing Robot Pattern is a method for writing UI tests. It divides the test
 1. You need to install the following tools.
 
 - JDK 17
-- Xcode, [.xcode-version](.xcode-version) version
-- Ruby, [.ruby-version](.ruby-version) version
+- Xcode, [`.xcode-version`](.xcode-version) version
+- Ruby, [`.ruby-version`](.ruby-version) version
   - bundler (you can install by `gem install bundler` or `sudo gem install bundler`)
 
 2. Setup
    1. `bundle install`
    2. `bundle exec fastlane build-kmm`
 
-3. open [app-ios.xcworkspace](./app-ios/app-ios.xcworkspace) by Xcode
+3. open [`app-ios.xcworkspace`](./app-ios/app-ios.xcworkspace) by Xcode
+
+## Build
+
+- You can filter XCFramework arch by `arch` option at [`local.properties`](./local.properties)
+  - ex), if you need only `x86_64` binary, you can set `arch=x86_64`