chore: add github repo banner

[warengonzaga]

This pull request adds a visual improvement to the project documentation by including a GitHub repository banner in the README.md file.

Documentation update:

• Added a GitHub Repo Banner image at the top of README.md to enhance the project's visual presentation.

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The banner is made using this tool: https://ghrb.waren.build/ (I made it)
Wondering if we can add this to this project to have some good visuals. (Just launched today, yey)

Greptile Overview

Greptile Summary

This PR updates project documentation by adding a GitHub README banner image near the top of README.md (under the existing badges) to improve visual presentation.

The change is isolated to documentation and does not affect runtime code paths or application behavior.

Confidence Score: 4/5

• This PR is safe to merge; it’s a documentation-only change with low blast radius.
• The only change is adding a README banner image. Main considerations are long-term reliability/maintainability of a remote, dynamically generated asset and minor markdown rendering portability.
• README.md (banner hosting/format choice)

_{(2/5) Greptile learns from your feedback when you react with thumbs up/down!}

Context used:

• Context from dashboard - AGENTS.md (source)

[vercel]

@warengonzaga is attempting to deploy a commit to the Amantus Machina Team on Vercel.

A member of the Team first needs to authorize it.

[warengonzaga]

This is the preview:

[greptile-apps]

_{1 file reviewed, 2 comments}

_{Edit Code Review Agent Settings | Greptile}

[greptile-apps]

[P1] Remote, dynamic banner can break or change unexpectedly

This embeds a remotely generated image (https://ghrb.waren.build/banner?...) with many query params. If that service has downtime/rate limits, changes output, or is blocked by some networks, the README header will render poorly. Consider committing a static banner image into the repo (or using a GitHub-hosted asset) and linking to the generator in a separate credit line.

_{Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!}

Prompt To Fix With AI

This is a comment left during a code review.
Path: README.md
Line: 9:9

Comment:
[P1] Remote, dynamic banner can break or change unexpectedly

This embeds a remotely generated image (`https://ghrb.waren.build/banner?...`) with many query params. If that service has downtime/rate limits, changes output, or is blocked by some networks, the README header will render poorly. Consider committing a static banner image into the repo (or using a GitHub-hosted asset) and linking to the generator in a separate credit line.

<sub>Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!</sub>

How can I resolve this? If you propose a fix, please make it concise.

[warengonzaga]

SVG version is also available for this, just let me know I can update this PR.