Add screenshots and images throughout the developer setup documentation

[coderNini]

Summary

The current developer setup documentation lacks visual aids. Detailed step-by-step walkthroughs would be much clearer with screenshots or annotated images at key steps.

Proposed Changes

• Add images to supplement step-by-step instructions throughout the documentation, especially in sections with multi-step UI flows (e.g., API key creation, Heroku setup)
• Prioritize sections where page transitions or UI interactions are described

Make changes in #408 (and refer to comments for further detail)

[beanscg]

Bean Labs took a public-source pass on this issue.

The narrowest useful next step looks like: Offer a scoped visual-aid audit comment that identifies developer setup steps where screenshots would help, especially API key creation/configuration and multi-step UI flows.

Public evidence checked:

• Live public issue read: open, no assignees, zero comments; body asks for images in developer setup docs, especially API key creation/configuration and multi-step UI flows.
• Public web search for repo pull requests tied to issue 428 returned no visible open PR coverage.

A good acceptance check would be a docs diff that changes only the affected wording/link and renders without stale references.

No PR opened from this pass.