Fix TRE GPU Service training links and index navigation

[umairayub38]

EIDF Documentation Pull Request

Description

This PR updates the TRE GPU Service documentation to improve navigation and correctness of internal links, particularly for training materials and related service pages.

The main changes include:

Updating index.md to include correct and complete links to training tutorials, policies, FAQ, and related pages.

Fixing broken or outdated relative links in multiple training documents so that prerequisite references resolve correctly within the documentation structure.

Fixes # (issue)

Type of change

Please delete options that are not relevant.

• Incorrect Documentation
• Incomplete Documentation
• Missing Documentation
• Formatting

What has to be reviewed

docs/safe-haven-services/tre-gpu-service/index.md

Links to training pages

Additional Service Information section

Training pages with updated prerequisite links:

training/L4_requesting_persistent_volumes.md

training/L5_running_a_pytorch_task.md

training/L6_template_workflow.md

Checklist

• Documentation follows the project style guidelines
• Ensure Contact details contain Service Emails and Numbers
• Self-review of documentation using mkdocs on local system
• Spellcheck has been performed
• Pre-commit has been run and passed

[kavousan]

Minor changes required.

[kavousan]

One minor change, sorry.