Fix typo in the timelines in the release notes

content/release/v2020.0/releasenotes.md

@@ -39,10 +39,10 @@ published quarterly, up to v2020.7.
   - 2020 Q2: v2020.1
   - 2020 Q3: v2020.2
   - 2020 Q4: v2020.3
-  - 2021 Q3: v2020.4
-  - 2021 Q1: v2020.5
-  - 2021 Q2: v2020.6
-  - 2021 Q3: v2020.7
+  - 2021 Q1: v2020.4
+  - 2021 Q2: v2020.5
+  - 2021 Q3: v2020.6
+  - 2021 Q4: v2020.7
 
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