Home page CTA and messaging misaligned with personal-finance

[gjong]

Labels: bug, content, priority:P0
Parent issue: Epic: Documentation site overhaul

Problem
The home page hero CTA links to /architecture/ instead of /getting-started/. Hero copy leans toward "teams" / "operational finance" language rather than personal-finance positioning. The Docker install link in content/_index.md (~line 43) is also miscategorized as How-To instead of Getting Started.

Suggested fix

• Point the hero CTA to /getting-started/ (or directly to /getting-started/installation/docker/).
• Rewrite hero copy to speak to individual/self-hosted personal-finance users.
• Fix the Docker install link to point at the Getting Started section.
• Unify terminology across the home page and nav (currently mixes "Reference guide"/"Explanations" with "Architecture"/"Financial concepts").

Acceptance criteria

• Hero CTA links to Getting Started.
• Hero copy reviewed and no longer uses "teams"/"operational finance" framing.
• Docker link fixed.
• Section naming consistent between home page and top nav.