updated whats new

Author: kthyng

docs/whats_new.md

@@ -1,6 +1,8 @@
 # What's New
 
-## v0.3.0 (unreleased)
+## v2.1.0 (unreleased)
 
 * Fixed a deprecation warning (https://github.com/matplotlib/cmocean/pull/86), by @neutrinoceros
-* Added CodeQL workflow (https://github.com/matplotlib/cmocean/pull/85), by bot
+* Added CodeQL workflow (https://github.com/matplotlib/cmocean/pull/85), by bot
+* Changed master to main, by @kthyng
+* Added new CI workflows (testing, dependabot) and added codecov (https://github.com/matplotlib/cmocean/pull/88), by @kthyng