Fix table of contents in 2.0.0-RCs changelog

Author: japgolly

doc/changelog/2.0.0-RCs.md

@@ -8,6 +8,7 @@ Contents:
 - [Changes in RC3](#changes-in-rc3)
 - [Changes in RC4](#changes-in-rc4)
 - [Changes in RC5](#changes-in-rc5)
+- [Changes in between RC5 and 2.0.0 final](#changes-in-between-rc5-and-200-final)
 
 
 # Changes in RC1