Add .editorconfig syntax highlighting (#401)

Author: GuyPago

README.md

@@ -42,10 +42,10 @@ dotnet add package FluentAssertions.Analyzers
 
 You can exclude assertion methods using the `.editorconfig` file:
 
-````
+```ini
 [*.cs]
 ffa_excluded_methods=M:NUnit.Framework.Assert.Fail;M:NUnit.Framework.Assert.Fail(System.String)
-````
+```
 
 ## Getting Started