chore: Update Website Navigation and Messaging

[shivasurya]

Description:

Changes

• Updated the main tagline to "Opensource alternative to CodeQL" for clearer positioning
• Added "Tech Blog" navigation link across main pages for better content discovery
• Enhanced navigation consistency between index and blog pages

Technical changes

• Modified hero section in both index.mdx and blog/index.mdx
• Added new navigation action with pen icon linking to blog section
• Aligned navigation structure across pages

Checklist:

• Tests passing (gradle testGo)?
• Lint passing (golangci-lint run this requires golangci-lint)?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 72.42%. Comparing base (833da9a) to head (8e238b9).
Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #197   +/-   ##
=======================================
  Coverage   72.42%   72.42%           
=======================================
  Files          16       16           
  Lines        2473     2473           
=======================================
  Hits         1791     1791           
  Misses        639      639           
  Partials       43       43           

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