Mention keyboard navigation in README

Author: asgerf

extensions/ql-vscode/README.md

@@ -99,6 +99,10 @@ When the results are ready, they're displayed in the CodeQL Query Results view.
 
 If there are any problems running a query, a notification is displayed in the bottom right corner of the application. In addition to the error message, the notification includes details of how to fix the problem.
 
+### Keyboad navigation
+
+If you wish to navigate the query results from your keyboard, you can bind shortcuts to the **CodeQL: Navigate Up/Down/Left/Right in Result Viewer** commands.
+
 ## What next?
 
 For more information about the CodeQL extension, [see the documentation](https://codeql.github.com/docs/codeql-for-visual-studio-code/). Otherwise, you could: