Add changelog for 7.17.7 release

Anaethelion · Anaethelion · commit 42a76f7ac369 · 2022-10-26T15:51:48.000+02:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,3 +1,10 @@
+# v7.17.7
+
+## Client
+
+* Added the option to override the `Content-Type` to enable usage of alternative serialization. ([#542](https://github.com/elastic/go-elasticsearch/pull/542))
+* API is compatible with Elasticsearch 7.17.7
+
 # v7.17.1
 
 ## Client
