fix: Add new Lumo West Coast routes

[lenderom]

Summary

• Updates the existing Lumo (LD) train category on the GB operator page from fip_accepted=true to fip_accepted=partially
• Describes both Lumo routes in a single train category entry:
  • East Coast Main Line: London King's Cross – Newcastle – Edinburgh (FIP accepted)
  • West Coast Main Line: Planned Spring 2026 launch by First Lumo Stirling from London Euston via Milton Keynes, Crewe, Preston and Carlisle to Stirling (FIP currently not valid)
• Adds RDG source as footnote [^7]

Closes #761

[github-actions]

Hi there! 👋

Thank you for your contribution to the FIP Guide! 🚀
We appreciate your effort in making rail staff travel information more accessible. 🚄

Checklist before merging:

• Added a description to the Pull Request
• Checked the License of new pictures (non-commercial use without attribution)
• Modified content in English
• Modified content in German
• Modified content in French

[MoritzWeber0]

Lumo West Coast doesn't seem to be another operator. We already have Lumo in the list, so we just need to mention the West coast line as part of it, I'd say. (https://en.wikipedia.org/wiki/Lumo_(train_operating_company))

[netlify]

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[lenderom]

Lumo West Coast doesn't seem to be another operator. We already have Lumo in the list, so we just need to mention the West coast line as part of it, I'd say. (https://en.wikipedia.org/wiki/Lumo_(train_operating_company))

The initial Commit was 100% AI created :D
I had to change this ^^

[MoritzWeber0]

LGTM