Mention removal of CryptoRngCore (#1562)

Closes #1561.

Author: dhardy

rand_core/CHANGELOG.md

@@ -15,7 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### API changes
 - Allow `rand_core::impls::fill_via_u*_chunks` to mutate source (#1182)
 - Add fn `RngCore::read_adapter` implementing `std::io::Read` (#1267)
-- Add trait `CryptoBlockRng: BlockRngCore`; make `trait CryptoRng: RngCore` (#1273)
+- Add trait `CryptoBlockRng: BlockRngCore`; make `trait CryptoRng: RngCore` replacing `CryptoRngCore` (#1273)
 - Add traits `TryRngCore`, `TryCryptoRng` (#1424, #1499)
 - Rename `fn SeedableRng::from_rng` -> `try_from_rng` and add infallible variant `fn from_rng` (#1424)
 - Rename `fn SeedableRng::from_entropy` -> `from_os_rng` and add fallible variant `fn try_from_os_rng` (#1424)