Add asciidoc release notes

Author: mjwolf

docs/release-notes/8.17.asciidoc

@@ -0,0 +1,18 @@
+[[ecs-release-notes-8.17.0]]
+=== 8.17.0
+
+[[schema-changes-8.17.0]]
+[float]
+==== Schema changes
+
+[[schema-bugfixes-8.17.0]]
+[float]
+===== Bugfixes
+* Fix link rendering issues and usage of http in links. {ecs_pull}2423[#2423]
+
+[[schema-improvements-8.17.0]]
+[float]
+===== Improvements
+
+* Increase ignore_above value for url.query. {ecs_pull}2424[#2424]
+* Set synthetic_source_keep = none on fields that represent sets. {ecs_pull}2422[#2422]