docs: refactor overview and start pages

[reubenmiller]

Proposed changes

Refactor the overview and start pages to reduce maintain by linking to other parts of the docs rather than listing individual pages within each section.

In addition the following minor tweak were made to improve the links within the pages:

• Use fixed anchor ids
• Use thin-edge.io name placeholder

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (general improvements like code refactoring that doesn't explicitly fix a bug or add any new functionality)
• Documentation Update (if none of the other choices apply)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Paste Link to the issue

#2628

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA (in all commits with git commit -s)
• I ran cargo fmt as mentioned in CODING_GUIDELINES
• I used cargo clippy as mentioned in CODING_GUIDELINES
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

[didier-wenzek]

Approved

[github-actions]

Robot Results

✅ Passed	❌ Failed	⏭️ Skipped	Total	Pass %	⏱️ Duration
383	0	3	383	100	1h0m33.800999999s