fix: change readme with ios simulator intructions

Author: juanky201271

README.md

@@ -7,12 +7,12 @@ Google Play: [https://play.google.com/store/apps/details?id=org.ZingoLabs.Zingo]
 1. Yarn
 2. NodeJS (recommended version 17+)
 3. Rust (https://www.rust-lang.org/tools/install)
-4. Rustup iOS targets (`rustup target add aarch64-apple-ios x86_64-apple-ios`)
+4. Rustup iOS targets (`rustup target add aarch64-apple-ios x86_64-apple-ios aarch64-apple-ios-sim`)
 5. Cargo-lipo (`cargo install cargo-lipo`)
 6. Cbindgen (`cargo install cbindgen`)
 7. Cocaopods (`sudo gem install cocoapods`)
 
-## Building
+## Building for physical device
 1. In the `rust/ios` directory, run: <br />
    `./build.sh` <br />
    This step may take a long time.
@@ -21,6 +21,15 @@ Google Play: [https://play.google.com/store/apps/details?id=org.ZingoLabs.Zingo]
 3. In the `ios` directory, run: <br />
    `pod install`
 
+## Building for simulator
+1. In the `rust/ios` directory, run: <br />
+   `./buildsimulator.sh` <br />
+   This step may take a long time.
+2. From the root of the project, run: <br />
+   `yarn`
+3. In the `ios` directory, run: <br />
+   `pod install`
+
 ## Launching the app
 1. In a terminal, run: <br />
    `yarn start`