Add updated deadlines to CfS

Author: James Clark

content/pages/sc20/call_for_submissions.md

@@ -76,9 +76,10 @@ Please keep accessibility in mind when preparing presentation slides. See our [a
 | Paper Submissions Due               | Friday 11 September |
 | Paper Author Notifications          | Monday 28 September |
 | Lightning Talk Submissions Due      | Thursday 1 October  |
+| Lightning Talk Author Notifications | Monday 5 October    |
 | Paper Camera Ready                  | Thursday 8 October  |
-| Lightning Talk Author Notifications | Monday 19 October   |
-| Paper Presentation Slides           | Monday 2 November   |
+| Paper Presentation Recordings       | Thursday 8 October  |
+| Lightning Talk Presentation Slides  | Thursday 8 October  |
 | Workshop Date                       | Friday 13 November  |
 
 ## Organizing Committee