Distinguish Python from Node.js release processes, mention release-it

Co-authored-by: David Glick <[email protected]>

Author: stevepiercy

docs/contributing/index.md

@@ -146,7 +146,9 @@ Volto
 
 The Plone [Release Team](https://plone.org/community/teams/release-team) manages the release of new versions of Plone.
 
-We use [`zest.releaser`](https://zestreleaser.readthedocs.io/en/latest/) for releasing the packages used in Plone, including [Plone core (`Products.CMFPlone`)](https://github.com/plone/Products.CMFPlone/), {doc}`Volto </volto/index>`, {doc}`/classic-ui/index`, {doc}`/plone.restapi/docs/source/index`, {doc}`/plone.api/index`, and {doc}`/backend/index`.
+We use [`zest.releaser`](https://zestreleaser.readthedocs.io/en/latest/) for releasing the Python packages used in Plone, including [Plone core (`Products.CMFPlone`)](https://github.com/plone/Products.CMFPlone/), {doc}`/classic-ui/index`, {doc}`/plone.restapi/docs/source/index`, {doc}`/plone.api/index`, and {doc}`/backend/index`.
+
+We use [`release-it`](https://github.com/release-it/release-it) for releasing the Node.js packages used in Plone, including {doc}`Volto </volto/index>` and the [Classic UI mockup](https://github.com/plone/mockup).
 
 
 ```{toctree}