Improve d3

[alourie]

Description

Improvements to Docusaurus 3 builds:

• Include node_modules in the pipeline container
• Expose port 3000 for in-container-serve
• Skip fetching dependencies if on Docusaurus 3
• Automatically repackage node_modules in the new container image, but only if package-lock.json changes.
• Fix local tests
• Add a helper script to run npm serve and npm start

Already tested with hosting-capacity-service repository on both Linux (myself) and Windows with @AlexV-ZB.

Should be complemented by merging zepben/docusaurus-action#14 after this.