Update what's new list on docs homepage

_data/whats_new.yml

@@ -1,9 +1,9 @@
-- date: "Feb 2021"
-  title: "Expanded Developer Guide"
-  summary: "Added several pages on <a href='stable/developer-guide-overview.html'>developing applications with CockroachDB</a>, including connecting to a cluster and schema design. More guidance coming soon."
-- date: "Feb 2021"
-  title: "TypeScript Hello World"
-  summary: "Added a tutorial on <a href='stable/build-a-typescript-app-with-cockroachdb.html'>building a TypeScript application</a> with CockroachDB and TypeORM."
-- date: "Jan 2020"
-  title: "Docs Site Redesign"
-  summary: "Updated the overall branding and the styling of important interactive elements such as tabs and code blocks, and added an embedded <a href='stable/sql-playground.html'>interactive SQL playground</a>."
+- date: "May 2021"
+  title: "CockroachDB v21.1"
+  summary: "With the release of CockroachDB v21.1, we've made a variety of flexibility, performance, and compatibility improvements. Check out the <a href='releases/v21.1.0.html'>v21.1 release notes</a> for details about the most significant user-facing changes and then <a href='v21.1/upgrade-cockroach-version.html'>upgrade to CockroachDB v21.1</a>."
+- date: "Apr 2021"
+  title: "Connection Pooling Guidance"
+  summary: "Added guidance on <a href='v21.1/connection-pooling.html'>planning, configuring, and using connection pools</a> with CockroachDB, as well as examples for Java and Go applications."
+- date: "Mar 2021"
+  title: "Sample Apps on CockroachCloud Free"
+  summary: "Updated various Java, Python, Node.js, Ruby, and Go <a href='v21.1/hello-world-example-apps.html'>sample app tutorials</a> to offer CockroachCloud Free as the backend."