docs: Update changelogs for 8.16 release (#14382)

Co-authored-by: obltmachine <150269514+obltmachine@users.noreply.github.com>
(cherry picked from commit b3c5d5f)

CHANGELOG.asciidoc

@@ -1,4 +1,5 @@
 // tag::list[]
+* <<apm-release-notes-8.16>>
 * <<apm-release-notes-8.15>>
 * <<apm-release-notes-8.14>>
 * <<apm-release-notes-8.13>>
@@ -18,7 +19,7 @@
 // end::list[]
 
 // tag::includes[]
-include::./changelogs/head.asciidoc[]
+include::./changelogs/8.16.asciidoc[]
 include::./changelogs/8.15.asciidoc[]
 include::./changelogs/8.14.asciidoc[]
 include::./changelogs/8.13.asciidoc[]

changelogs/8.16.asciidoc

@@ -0,0 +1,31 @@
+[[apm-release-notes-8.16]]
+== APM version 8.16
+* <<apm-release-notes-8.16.0>>
+
+[float]
+[[apm-release-notes-8.16.0]]
+=== APM version 8.16.0
+
+https://github.com/elastic/apm-server/compare/v8.15.2\...v8.16.0[View commits]
+
+[float]
+==== Bug fixes
+
+- Track all bulk request response status codes {pull}13574[13574]
+- Fix a concurrent map write panic in monitoring middleware {pull}14335[14335]
+- Apply shutdown timeout to http server {pull}14339[14339]
+
+[float]
+==== Breaking Changes
+
+[float]
+==== Deprecations
+- Support for Jaeger is now deprecated, and will be removed in a future release {pull}13809[13809]
+
+[float]
+==== Intake API Changes
+
+[float]
+==== Added
+
+- APM Server will no longer retry an HTTP request that returned 502s, 503s, 504s. It will only retry 429s. {pull}13523[13523]

changelogs/head.asciidoc

@@ -1,26 +1,16 @@
 [[release-notes-head]]
 == APM version HEAD
 
-https://github.com/elastic/apm-server/compare/8.15\...main[View commits]
-
-[float]
-==== Bug fixes
-
-- Track all bulk request response status codes {pull}13574[13574]
-- Fix a concurrent map write panic in monitoring middleware {pull}14335[14335]
-- Apply shutdown timeout to http server {pull}14339[14339]
+https://github.com/elastic/apm-server/compare/8.16\...8.x[View commits]
 
 [float]
 ==== Breaking Changes
 
 [float]
 ==== Deprecations
-- Support for Jaeger is now deprecated, and will be removed in a future release {pull}13809[13809]
 
 [float]
 ==== Intake API Changes
 
 [float]
 ==== Added
-
-- APM Server will no longer retry an HTTP request that returned 502s, 503s, 504s. It will only retry 429s. {pull}13523[13523]