Updated CHANGELOG and docs for 8.4 release

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Changelog
 
+## 8.4.0 (2022-08-24)
+
+Release compatible with Enterprise Search, App Search and Workplace Search 8.3.
+
+This release includes the following fixes:
+
+- Fixed 8.1 deprecation warning for ArrayAccess::offsetGet()
+  [#25](https://github.com/elastic/enterprise-search-php/pull/25)
+
 ## 8.3.0 (2022-07-08)
 
 Release compatible with Enterprise Search, App Search and Workplace Search 8.3

docs/guide/release_notes/84.asciidoc

@@ -0,0 +1,14 @@
+[[release_notes_84]]
+=== 8.4 Release notes
+
+[discrete]
+[[release_notes_840]]
+=== 8.4.0 Release notes
+
+Release created to be compatible with the **8.4** API of https://www.elastic.co/enterprise-search[Enterprise Search], https://www.elastic.co/app-search/[App Search] and https://www.elastic.co/workplace-search[Workplace Search].
+
+This release includes also the following fix:
+
+- Fixed 8.1 deprecation warning for ArrayAccess::offsetGet()
+  https://github.com/elastic/enterprise-search-php/pull/25[#25]
+

docs/guide/release_notes/index.asciidoc

@@ -4,11 +4,13 @@
 [discrete]
 === 8.x
 
+* <<release_notes_84, 8.4.0 Release Notes>>
 * <<release_notes_83, 8.3.0 Release Notes>>
 * <<release_notes_82, 8.2.0 Release Notes>>
 * <<release_notes_81, 8.1.0 Release Notes>>
 * <<release_notes_80, 8.0.0 Release Notes>>
 
+include::84.asciidoc[]
 include::83.asciidoc[]
 include::82.asciidoc[]
 include::81.asciidoc[]