Update changelog with breaking changes

CHANGELOG.md

@@ -7,14 +7,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [0.26.0] - 2023-09-02
 * MSRV raised to 1.71
-* All traits converted to AFIT, except `Unblocker`, which needs to compile with stable Rust
-* Upgraded to `embedded-io` 0.5 and `embedded-io-async` 0.5
+* Breaking change: All traits converted to AFIT, except `Unblocker`, which needs to compile with stable Rust
+* Breaking change: Upgraded to `embedded-io` 0.5 and `embedded-io-async` 0.5
 * Upgraded `strum` and `strum-macros` to 0.25
-* OTA: GAT `Ota::Update` now parametric over lifetime and no longer returned by `&mut` ref
-* MQTT: GAT `Connection::Message` now parametric over lifetime
-* All pub structs in `utils::asyncify` that implement the `Future` trait are now private and wrapped with async methods
-* Removed structs `Blocking` and `TrivialAsync`, as well as all trait implementations on them, because their usefulness was questionable
-* Removed the deprecated module `httpd` and the dependency on `anyhow`
+* Breaking change: OTA: GAT `Ota::Update` now parametric over lifetime and no longer returned by `&mut` ref
+* Breaking change: MQTT: GAT `Connection::Message` now parametric over lifetime
+* Breaking change: All pub structs in `utils::asyncify` that implement the `Future` trait are now private and wrapped with async methods
+* Breaking change: Removed structs `Blocking` and `TrivialAsync`, as well as all trait implementations on them, because their usefulness was questionable
+* Breaking change: Removed the deprecated module `httpd` and the dependency on `anyhow`
 
 ## [0.25.3] - 2023-07-05
 * Compatibility with latest Rust nightly Clippy (fixes the "usage of `Arc<T>` where `T` is not `Send` or `Sync`" error)