chore(CHANGELOG): update to v9.0.0-alpha.0

CHANGELOG.md

@@ -2,10 +2,15 @@
 
 All notable changes to [bpmn-js](https://github.com/bpmn-io/bpmn-js) are documented here. We use [semantic versioning](http://semver.org/) for releases.
 
+
 ## Unreleased
 
 ___Note:__ Yet to be released changes appear here._
 
+## 9.0.0-alpha.0
+
+* `FEAT`: support drilldown into collapsed subprocesses ([#1443](https://github.com/bpmn-io/bpmn-js/issues/1443)) 
+* `CHORE`: bump to `diagram-js@8.0.1`
 ### Breaking Changes
 
 * Reworked the link of elements to bpmn DIs. You must access the `di` directly from the diagram element instead of the `businessObject`. [#1472](https://github.com/bpmn-io/bpmn-js/issues/1472)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "bpmn-js",
-  "version": "9.0.0-subprocesses.3",
+  "version": "8.8.4",
   "description": "A bpmn 2.0 toolkit and web modeler",
   "main": "index.js",
   "files": [