Update README to clarify binding generation and repo layout

Clarifies that Dart bindings and the native library are generated locally and not checked into the repository. Updates repository layout descriptions and setup instructions to reflect this, and specifies that binding generation requires a macOS or Linux host. Also refines test descriptions for accuracy.

Author: Aniket-pd

README.md

@@ -1,18 +1,19 @@
 # bdk-dart
 
 Dart bindings for the [Bitcoin Dev Kit (BDK)](https://bitcoindevkit.org/) wallet library.
-The repo packages the generated UniFFI bindings (`lib/bdk.dart`) together with the
-compiled `libbdkffi` native library so Dart and Flutter apps can work with descriptor-based
-wallets, key management utilities, and blockchain backends from BDK.
+The repo contains the sources for generating UniFFI-based bindings (`lib/bdk.dart`) and the
+`libbdkffi` native library, both of which are produced locally (they are gitignored and not
+checked into the repository) so Dart and Flutter apps can work with descriptor-based wallets,
+key management utilities, and blockchain backends from BDK.
 
 ## Repository layout
 
 | Path | Purpose |
 | ---- | ------- |
 | `bdk-ffi/` | Rust sources and build scripts for the underlying `bdk-ffi` crate. |
-| `lib/` | Generated Dart bindings (`bdk.dart`) produced by UniFFI-Dart. |
+| `lib/` | Dart bindings (`bdk.dart`) generated locally by UniFFI-Dart. |
 | `examples/` | Standalone Dart examples that exercise common workflows. |
-| `test/` | Integration-style tests that cover wallet creation, persistence, and networking. |
+| `test/` | Offline/construction/persistence tests (not full integration tests). |
 | `bdk_demo/` | Flutter sample app you can point at mobile targets once the bindings are built. |
 | `scripts/generate_bindings.sh` | Helper used to rebuild the native library and regenerate the Dart bindings. |
 
@@ -38,7 +39,7 @@ cd bdk-dart
    ```bash
    dart pub get
    ```
-2. Generate the Dart bindings and native binary:
+2. Generate the Dart bindings and native binary (requires a macOS or Linux host):
    ```bash
    ./scripts/generate_bindings.sh
    ```
@@ -70,8 +71,8 @@ build steps or platform-specific build scripts).
 
 ## Testing
 
-Once `lib/bdk.dart` and the native library are available you can execute the Dart test
-suite, which covers wallet creation, persistence, offline behavior, and descriptor APIs:
+Once you have generated `lib/bdk.dart` and the native library locally you can execute the
+Dart test suite, which covers wallet creation, persistence, offline behavior, and descriptor APIs:
 
 ```bash
 dart test