[DOCS] Add Elastic Security breaking changes to Installation and Upgrade Guide for 8.3 (#2148)

(cherry picked from commit 5ad3225)

# Conflicts:
#	docs/en/install-upgrade/breaking.asciidoc

Author: nastasha-solomon

docs/en/install-upgrade/breaking.asciidoc

@@ -65,10 +65,17 @@ include::{es-repo-dir}/migration/migrate_8_3.asciidoc[tag=notable-breaking-chang
 <titleabbrev>{elastic-sec}</titleabbrev>
 ++++
 
+<<<<<<< HEAD
 This list summarizes the most important breaking changes in {elastic-sec} {version}.
 //For the complete list, go to {security-guide-all}/8.3/release-notes-header-8.2.0.html#breaking-changes-8.2.0[{elastic-sec} breaking changes].
 
 //include::{security-repo-dir}/release-notes/8.3.asciidoc[tag=breaking-changes]
+=======
+This list summarizes the most important breaking changes in {elastic-sec} {version}. For
+the complete list, go to {security-guide-all}/8.3/release-notes-header-8.3.0.html#breaking-changes-8.3.0[{elastic-sec} breaking changes].
+
+include::{security-repo-dir}/release-notes/8.3.asciidoc[tag=breaking-changes]
+>>>>>>> 5ad3225 ([DOCS] Add Elastic Security breaking changes to Installation and Upgrade Guide for 8.3 (#2148))
 
 [[kibana-breaking-changes]]
 === {kib} breaking changes