10.4.0 release notes (#4171)

* Mention the new license and the dependency reuirement

docs/src/main/paradox/release-notes/10.4.x.md

@@ -0,0 +1,23 @@
+# 10.4.x release notes
+
+## 10.4.0
+
+This release is the first under the new BSL license. For details about why the license is changing see [Why We Are Changing the License for Akka](https://www.lightbend.com/blog/why-we-are-changing-the-license-for-akka). Additionally the [detailed FAQ](https://www.lightbend.com/akka/license-faq) is available to answer many of
+the questions that you may have about the license change. 
+
+Akka 10.4.0 requires Akka 2.7.0 and will not work with earlier versions of Akka. Except for that it should be a drop in 
+replacement for Akka HTTP 10.2.x.
+
+The release also includes a few dependency updates and one small improvement
+
+### Changes since 10.2.10
+
+#### akka-http-core
+
+* Update naming for status codes 413 and 422 [#4165](https://github.com/akka/akka-http/pull/4165)
+
+#### Dependency updates
+
+* Scala 2.12.17 & 2.13.10 [#4168](https://github.com/akka/akka-http/pull/4168)
+* Jackson Databind 2.13.4.2 [#4172](https://github.com/akka/akka-http/pull/4172)
+

docs/src/main/paradox/release-notes/index.md

@@ -4,6 +4,7 @@
 
 @@@ index
 
+* [10.4.x](10.4.x.md)
 * [10.2.x](10.2.x.md)
 * [10.1.x](10.1.x.md)
 * [10.0.x](10.0.x.md)