Update CHANGELOG.md file on release (neo4j#57)

Add section for current release

Author: oskarhane

.github/workflows/prerelease.yaml

@@ -34,10 +34,13 @@ jobs:
       - name: Print varaibles
         run: |
           echo Version: ${{ steps.get-version.outputs.version }}
+      - name: Update CHANGELOG.md (cross platform supported)
+        run: |
+          sed -i.bak -e 's/## Next/## Next\n\n## ${{ steps.get-version.outputs.version }}/' CHANGELOG.md && rm CHANGELOG.md.bak
       - uses: EndBug/add-and-commit@v9
         with:
           author_name: 'Neo4j-GenAI GitHub Action'
           author_email: 'team-gen-ai@neo4j.com'
           message: 'Bump version to ${{ steps.get-version.outputs.version }}'
-          add: 'pyproject.toml'
+          add: "['pyproject.toml', 'CHANGELOG.md']"
           tag: '${{ steps.get-version.outputs.version }}'