Add SE-0269 to the changelog (#29285)

* Add SE-0269 to the changelog

* Add missing quote

* Add link for SE-0269

* Add swift language annotation to code block

Co-Authored-By: Suyash Srijan <suyashsrijan@outlook.com>

* Fix typo

Co-authored-by: Suyash Srijan <suyashsrijan@outlook.com>

Author: Jumhyn

CHANGELOG.md

@@ -23,6 +23,33 @@ CHANGELOG
 
 </details>
 
+Swift Next
+----------
+
+* [SE-0269][]:
+
+  When an escaping closure explicitly captures `self` in its capture list, the
+  use of implicit `self` is enabled within that closure. This means that the
+  following code is now valid:
+  
+  ```swift
+  func doStuff(_ stuff: @escaping () -> Void) {}
+  
+  class C {
+      var x = 0
+      
+      func method() {
+          doStuff { [self] in
+              x += 1
+          }
+      }
+  }
+  ```
+  
+  This proposal also introduces new diagnostics for inserting `self` into the
+  closure's capture list in addition to the existing 'use `self.` explicitly'
+  fix-it.
+
 Swift 5.2
 ---------
 
@@ -7856,6 +7883,7 @@ Swift 1.0
 [SE-0252]: <https://github.com/apple/swift-evolution/blob/master/proposals/0252-keypath-dynamic-member-lookup.md>
 [SE-0253]: <https://github.com/apple/swift-evolution/blob/master/proposals/0253-callable.md>
 [SE-0254]: <https://github.com/apple/swift-evolution/blob/master/proposals/0254-static-subscripts.md>
+[SE-0269]: <https://github.com/apple/swift-evolution/blob/master/proposals/0269-implicit-self-explicit-capture.md>
 
 [SR-106]: <https://bugs.swift.org/browse/SR-106>
 [SR-419]: <https://bugs.swift.org/browse/SR-419>