README tweak

Author: RalfJung

README.md

@@ -48,8 +48,8 @@ in your program, and cannot run all programs:
   has no access to most platform-specific APIs or FFI. A few APIs have been
   implemented (such as printing to stdout) but most have not: for example, Miri
   currently does not support SIMD or networking.
-* Miri currently does not check for data-races and most other concurrency
-  related issues.
+* Miri currently does not check for data-races and most other concurrency-related
+  issues.
 
 [rust]: https://www.rust-lang.org/
 [mir]: https://github.com/rust-lang/rfcs/blob/master/text/1211-mir.md