Rewrite Parts 3 and 4 for starter repo workflow with Python/Go tabs

Part 3: Replace viam module generate scaffolding with starter repo
workflow. Add Python as a second language option with Go/Python tabs
for prerequisites, code walkthrough, implementation, and iteration.

Part 4: Replace generator references with starter repo. Add Python/Go
tabs for module structure review and build/package/upload steps. Add
namespace setup and module registration steps.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: shannonbradshaw