Documentation: order of Navi items

[leape]

We want to set the order of all navigation items in the side navigation by the order property no matter if the file is .astro or .md.

Current Order

• Get Started
• Foundation
  • Border Radius
  • Border Width
  • Colors
  • Elevation
  • Opacity
  • Sizing
  • Spacing
• Components
  • all components
• Resources
• Releases
  • Migration Guides
    • v4.0.0
    • v3.0.0
    • v2.0.0
    • v1.0.0
  • Content Status
  • Versioning & Releases
  • Release Notes
  • Contribution
• Icons

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Expected:

• Get Started
• Foundation
  • Border Radius
  • Border Width
  • Colors
  • Elevation
  • Opacity
  • Sizing
  • Spacing
• Components
  • all components
• Icons
• Resources
• Releases
  • Release Notes
  • Migration Guides
    • v4.0.0
    • v3.0.0
    • v2.0.0
    • v1.0.0
  • Versioning & Releases
  • Content Status
• Contribution