Corrected bad language ID (#1614)

Ron Petrusha · web-flow · commit 40853cacd380 · 2019-10-10T21:09:07.000Z
diff --git a/async/async-and-await/cs/readme.md b/async/async-and-await/cs/readme.md
@@ -1,6 +1,6 @@
 ---
 languages:
-- cs
+- csharp
 products:
 - dotnet-core
 - windows
