Update changelog

CHANGELOG.md

@@ -1,4 +1,20 @@
+## 0.2.0 (January 15, 2021)
+
+Add support for all national clouds:
+
+- Global: graph.microsoft.com
+- Germany: graph.microsoft.de
+- China: microsoftgraph.chinacloudapi.cn
+- US Government L4: graph.microsoft.us
+- US Government L5 (DOD): dod-graph.microsoft.us
+
+Note that this is a breaking change from v0.1.0 as the signatures for all the clients have changed.
+If you are using the global cloud, you do not need to specify this when creating a new client as it is the default.
+However, you do need to specify a cloud environment when acquiring an access token using auth.NewAuthorizer.
+
+
 ## 0.1.0 (January 13, 2021)
+
 Initial release. Working support for:
 
 - Applications