Added screenshots to readme

Author: Giorgi

README.md

@@ -18,3 +18,9 @@ To install the visualizer as a LINQPad plugin download the [latest release](http
 
 ## Viewing query plan
 To view query plan or missing indexes call static `QueryPlanVisualizer.DumpPlan(query)` method or call `DumpPlan` extension method on any `IQueryable` instance. You will also need to add `ExecutionPlanVisualizer` to namespaces list (click F4 to open the dialog). If you want to dump query result too just pass `true` as a second parameter.
+
+Query execution plan:
+![query plan](screenshots/Query Plan.PNG "Query execution plan inside LINQPad")
+
+Missing index:
+![missing indexes](screenshots/Missing Index.PNG "Missing index")