docs: update formatting section in readme

Author: GNMoseke

README.md

@@ -2,12 +2,13 @@
 
 ## Contributing
 ### Code Formatting
-This package makes use of [swift-format](https://github.com/swiftlang/swift-format), which is built directly into the swift toolchain as of
-swift 6. To apply formatting rules to all files, which you should do before submitting a PR, run from the root of the repository:
+This package makes use of [SwiftFormat](https://github.com/nicklockwood/SwiftFormat?tab=readme-ov-file#command-line-tool), which you can install
+from [homebrew](https://brew.sh/). 
+
+To apply formatting rules to all files, which you should do before submitting a PR, run from the root of the repository:
 
 ```sh
-swift format --in-place --recursive .
+swiftformat .
 ```
-
 Formatting is validated with the `--strict` flag on every PR