Update release notes

Author: ovitrif

RELEASE-NOTES.txt

@@ -3,7 +3,7 @@
 20.5
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 * [*] Use larger thumbnail previews for recommended themes during site creation [https://github.com/wordpress-mobile/WordPress-Android/pull/16848]
-
+* [*] Jetpack App: Use the Jetpack green color for the skip buttons text in site creation [https://github.com/wordpress-mobile/WordPress-Android/pull/16994]
 
 20.4
 -----