Documents UI version 2 - Webpack and sandbox installation

[mark-terminusdb]

Additions and enhancements for documents UI version 2 documentation:

• Essential - add a Webpack installation guide to getting started: https://terminusdb.com/docs/index/terminusx-db/how-to-guides/generate-document-user-interfaces/get-started-with-the-documents-user-interface
• Optional - Documents UI with Common or Node JS (if possible)
• Optional - enable Sandboxed code examples