Update 4x changelog (#1605)

* update changelog

* add missing info

* change title

* add 4.21.0 changelog

en/changelog/4x.md

@@ -8,22 +8,48 @@ redirect_from: "/changelog/4x.html"
 
 # Release Change Log
 
+## 4.21.0 - Release date: 2024-09-11
+{: id="4.21.0"}
+
+The 4.21.0 minor release includes one new feature:
+
+* Deprecate `res.location("back")` and `res.redirect("back")` magic string
+
+## 4.20.0 - Release date: 2024-09-10
+{: id="4.20.0"}
+
+The 4.20.0 minor release includes bug fixes and some new features, including:
+
+* The [`res.clearCookie()` method](/{{ page.lang }}/4x/api.html#res.clearCookie) deprecates `options.maxAge` and `options.expires` options.
+* The [`res.redirect()` method](/{{ page.lang }}/4x/api.html#res.redirect) removes HTML link rendering.
+* The [`express.urlencoded()` method](/{{ page.lang }}/4x/api.html#express.urlencoded) method now has a depth level of `32`, whereas it was previously `Infinity`.
+* Adds support for named matching groups in the routes using a regex
+* Removes encoding of `\`, `|`, and `^` to align better with URL spec
+
+For a complete list of changes in this release, see [History.md](https://github.com/expressjs/express/blob/master/History.md#4200--2024-09-10)
+
 ## 4.19.2 - Release date: 2024-03-25
 {: id="4.19.2"}
 
 * Improved fix for open redirect allow list bypass
 
+For a complete list of changes in this release, see [History.md](https://github.com/expressjs/express/blob/master/History.md#4192--2024-03-25)
+
 ## 4.19.1 - Release date: 2024-03-20
 {: id="4.19.1"}
 
 * Allow passing non-strings to res.location with new encoding handling checks
 
+For a complete list of changes in this release, see [History.md](https://github.com/expressjs/express/blob/master/History.md#4191--2024-03-20)
+
 ## 4.19.0 - Release date: 2024-03-20
 {: id="4.19.0"}
 
 * Prevent open redirect allow list bypass due to encodeurl
 * deps: [email protected]
 
+For a complete list of changes in this release, see [History.md](https://github.com/expressjs/express/blob/master/History.md#4190--2024-03-20)
+
 ## 4.18.3 - Release date: 2024-02-29
 {: id="4.18.3"}