fix 16.13 blog post date (#2782)

as well the right link to the changelog

Author: Sunil Pai

content/blog/2020-03-02-react-v16.13.0.md renamed to content/blog/2020-02-26-react-v16.13.0.md

@@ -1,5 +1,5 @@
 - title: '16.13.0'
-  changelog: https://github.com/facebook/react/blob/master/CHANGELOG.md#16130-march-2-2020
+  changelog: https://github.com/facebook/react/blob/master/CHANGELOG.md#16130-february-26-2020
 - title: '16.12.0'
   changelog: https://github.com/facebook/react/blob/master/CHANGELOG.md#16120-november-14-2019
 - title: '16.11'