[ui5-server][INTERNAL] npm release: Add missing CHANGELOG file

The CLI needs the changelog files of all modules to create a
consolidated changelog.

Since npm v7 the CHANGELOG file is not always published anymore.
See: npm/npm-packlist#61

Author: matz3

packages/server/package.json

@@ -44,6 +44,7 @@
 	},
 	"files": [
 		"index.js",
+		"CHANGELOG.md",
 		"CONTRIBUTING.md",
 		"jsdoc.json",
 		"lib/**",