Fix a very small typo
a very small typo. IOS -> iOS.
@@ -49,4 +49,4 @@ Google's protocol buffers. See its
## Running on GNU/Linux ##
-To build and run on GNU/Linux, install [the Darling project](http://www.darlinghq.org/), then following [its Compile and Run a Program example](https://wiki.darlinghq.org/what_to_try#compile_and_run_a_program). Please note that j2objc is only supported on IOS/macOS.
+To build and run on GNU/Linux, install [the Darling project](http://www.darlinghq.org/), then following [its Compile and Run a Program example](https://wiki.darlinghq.org/what_to_try#compile_and_run_a_program). Please note that j2objc is only supported on iOS/macOS.
