CSE-1: spelling

Author: Vittel

README.md

@@ -19,7 +19,7 @@ The severity of individual rules may be configured using [rule set files](https:
 in Visual Studio 2015 or newer. **Settings.StyleCop** is not supported, but a **stylecop.json** file may be used to
 customize the behavior of certain rules. See [Configuration.md](documentation/Configuration.md) for more information.
 
-For documentation and reasoning on the rules themself, see the [Documentation](DOCUMENTATION.md).
+For documentation and reasoning on the rules themselves, see the [Documentation](DOCUMENTATION.md).
 
 For users upgrading from StyleCop Classic, see [KnownChanges.md](https://github.com/DotNetAnalyzers/StyleCopAnalyzers/tree/master/documentation/KnownChanges.md)
 for information about known differences which you may notice when switching to StyleCop Analyzers.