Update rx.lite.md

Author: 38elements

doc/libraries/rx.lite.md

@@ -52,6 +52,7 @@ NuGet Packages:
 - [`concat`](../api/core/operators/concatproto.md)
 - [`concatMap`](../api/core/operators/concatmap.md)
 - [`connect`](../api/core/operators/connect.md)
+- [`debounce`](../api/core/operators/debounce.md)  
 - [`defaultIfEmpty`](../api/core/operators/defaultifempty.md)
 - [`delay`](../api/core/operators/delay.md)
 - [`dematerialize`](../api/core/operators/dematerialize.md)