Add changelog entry

Author: marc-gr

spec/changelog.yml

@@ -10,6 +10,12 @@
     - description: Add support for semantic_text field definition.
       type: enhancement
       link: https://github.com/elastic/package-spec/pull/807
+    - description: Add support for _dev/shared folder.
+      type: enhancement
+      link: https://github.com/elastic/package-spec/pull/888
+    - description: Add support for *.link files in agent, pipelines, and fields folders.
+      type: enhancement
+      link: https://github.com/elastic/package-spec/pull/888
 - version: 3.3.4
   changes:
     - description: Remove slo assets when spec versions are less than 3.4.0.