Add changelog for actix-identity (#258)

actix-identity/CHANGES.md

@@ -1,7 +1,39 @@
 # Changes
 
-## Unreleased - 2022-xx-xx
+## 0.5.0 - 2022-xx-xx
+
+`actix-identity:0.5.0` is a complete rewrite. The goal is to streamline user experience and reduce maintenance overhead.  
+
+`actix-identity:0.5.0` is designed as an additional layer on top of `actix-session:0.7.x`, focused on identity management.  
+The identity information is stored in the session state, which is managed by `actix-session` and can be stored using any of the supported `SessionStore` implementations. This reduces the surface area in `actix-identity` (it is no longer concerned with cookies!) and provides a smooth upgrade path for users: if you need to work with sessions, you no longer need to choose between `actix-session` and `actix-identity`; they work together now!
+
+`actix-identity:0.5.0` has feature-parity with `actix-identity:0.4.x` - if you bump into any blocker when upgrading, please open an issue.
+
+Changes:
+
 - Minimum supported Rust version (MSRV) is now 1.57 due to transitive `time` dependency.
+- `IdentityService`, `IdentityPolicy` and `CookieIdentityPolicy` have been replaced by `IdentityMiddleware`. [#246]
+- `RequestIdentity` has been replaced by `IdentityExt`. [#246]
+- Trying to extract an `Identity` for an unauthenticated user will return a `401` response to the caller. Extract an `Option<Identity>` or a `Result<Identity, actix_web::Error>` if you need to work with users that may or may not be authenticated [#246]. Example:
+
+```rust
+use actix_web::{http::header::LOCATION, get, HttpResponse, Responder};
+use actix_identity::Identity;
+
+#[get("/")]
+async fn index(user: Option<Identity>) -> impl Responder {
+    if let Some(user) = user {
+        HttpResponse::Ok().finish()
+    } else {
+        // Redirect to login page if unauthenticated
+        HttpResponse::TemporaryRedirect()
+            .insert_header((LOCATION, "/login"))
+            .finish()
+    }
+}
+```
+
+[#246]: https://github.com/actix/actix-extras/pull/246
 
 
 ## 0.4.0 - 2022-03-01