Add changelog for 25.4.0

Author: chadlwilson

source/includes/changelog/_25-4-0.md.erb

@@ -0,0 +1,13 @@
+## Changes in 25.4.0
+
+### Added
+
+- No additions in this release
+
+### Removed
+
+- No removals in this release
+
+### Deprecations
+
+- <%= deprecated_api_message({api_name: 'Feeds', deprecated_in_release: '25.4.0', old_api_version: 1, new_api_version: nil, api_section: 'feeds', removal_in_release: '26.1.0'}) %>