Phase 1: Rewrite docs/index.md landing page

[kristopherjturner]

Parent Epic: #3

Description

Rewrite the docs/index.md landing page from the current placeholder into a comprehensive training curriculum overview.

Tasks

• Write training overview section (what this curriculum covers)
• Define target audience (Infrastructure Ops, SysAdmins, Cloud Admins)
• List prerequisite knowledge (Azure fundamentals, Windows Server, networking basics)
• Create module summary table (all 11 modules with descriptions and durations)
• Add delivery options section (remote, on-site, self-paced)
• Add duration estimates per module and total curriculum time
• Add quick-start links to each module
• Keep the existing placeholder warning admonition until content is complete
• Link to the delivery guide

Acceptance Criteria

• Landing page provides clear curriculum overview
• All 11 modules are listed with descriptions
• Delivery options and duration estimates are included
• Placeholder warning is preserved

[kristopherjturner]

Tracked in Azure DevOps: https://dev.azure.com/hybridcloudsolutions/Azure%20Local%20Training/_workitems/edit/208