docs: add DeepWiki badge

[kowanietz]

Summary

Add the DeepWiki badge to the repository README.

DeepWiki maintains automatically generated documentation for the Maka codebase. Adding the badge serves two purposes:

• allows DeepWiki to detect the repository integration and auto-refresh the documentation periodically
• gives contributors a quick entry point to the generated Maka documentation

DeepWiki provides automatically generated documentation and code cross-references for Maka, giving contributors another way to navigate and understand the codebase.

DeepWiki is free for open source repositories.

Verification

The badge renders correctly and links to the Maka DeepWiki

AI use

Select exactly one:

• No generative tool made a substantive contribution
• Generative tooling made a substantive contribution

Tool(s) and scope:

Checklist

• Tests cover the change and fail without it
• Lint, format, typecheck and the affected suites pass locally

Does this PR entail a change in behavior?

• Yes — described under Summary above
• No

[Astro-Han]

Approve.

I checked the precedent rather than assuming: this badge is already common across the foundation — apache/pulsar, apache/pinot, apache/ozone, apache/opendal, apache/seatunnel, apache/shenyu, apache/hertzbeat, apache/fluss, apache/cloudberry, apache/amoro, apache/iceberg-cpp and the whole apache/hugegraph family all carry it. So there is no foundation-level objection here, and I don't have a project-level one either.

Two small things, neither blocking:

• Please mirror this into README.zh-CN.md. This repository maintains the English and Chinese READMEs side by side, and the Chinese one carries the same badge row (README.zh-CN.md:32). Adding it in only one leaves Chinese readers without the link. Happy to approve again once that's in.
• Cosmetic: the badge currently lands after the macOS/Windows/Linux trio, splitting the platform badges from each other. Placing it right after the license badge keeps the three platform badges adjacent.

AI-assisted review disclosure: Claude Code ran the cross-repository badge search; I verified the hit list and the README badge structure myself.

[kowanietz]

• Please mirror this into README.zh-CN.md. This repository maintains the English and Chinese READMEs side by side, and the Chinese one carries the same badge row (README.zh-CN.md:32). Adding it in only one leaves Chinese readers without the link. Happy to approve again once that's in.
• Cosmetic: the badge currently lands after the macOS/Windows/Linux trio, splitting the platform badges from each other. Placing it right after the license badge keeps the three platform badges adjacent.

Done :)

[kowanietz]

Btw, the badge doesn't really match the other ones but I'm not sure if altering it breaks the integration. If a matching style is important, it might be worth a try.

[Astro-Han]

@M4n5ter - pulling you in on this one, since you have more context on this class of tooling than I do.

Two things worth your judgement, neither of which I want to decide alone:

1. Do we want the link at all? The badge points at DeepWiki's AI-generated documentation for this repository - content we do not control, cannot review, and which can change without us knowing. I checked the precedent and it is common across the foundation (apache/pulsar, apache/pinot, apache/ozone, apache/opendal, apache/seatunnel, apache/hertzbeat and others all carry it), so there is no foundation-level objection. It is a project taste call.

2. The visual mismatch, and whether fixing it breaks the integration. As @kowanietz points out, the badge does not match the row: deepwiki.com/badge.svg is a fixed SVG that ignores query parameters (I checked - ?style=flat returns identical bytes) and carries a linearGradient, while every other badge here is img.shields.io/...?style=flat, flat and gradient-free. A matching badge is one line:

   <a href="https://deepwiki.com/apache/maka"><img src="https://img.shields.io/badge/DeepWiki-Ask-4C8DFF?style=flat" alt="Ask DeepWiki" /></a>

   The stated cost is that DeepWiki's auto-refresh detection probably keys on a reference to their own badge.svg. Do you know whether that is actually how it works?

The change itself is clean and both READMEs are in sync - this is purely about whether we want it and in what form.

[M4n5ter]

English

Thanks for pulling me in. I am in favor of adding it, with a small visible trust boundary.

Please keep the official badge.svg: DeepWiki says repositories with its badge are auto-refreshed, while I found no public guarantee that a custom Shields badge is detected. I also found no published placement requirement, so I suggest putting it in a separate compact row below the project badges in both READMEs:

<sub>Third-party AI-generated docs · <a href="./docs/README.md">non-authoritative</a></sub>

中文

感谢邀请。我支持加入，但建议用一行很小的可见文字明确其信任边界。

请保留官方 badge.svg：DeepWiki 说明带有其 badge 的仓库会自动刷新，但没有公开保证自定义 Shields badge 也会被识别。我也没有找到对 badge 位置的公开要求，因此建议在两个 README 的项目徽章下方另起一行紧凑展示：

<sub>第三方 AI 生成文档 · <a href="./docs/README.md">非权威来源</a></sub>

[M4n5ter]

Verified the final README placement and the visible third-party AI documentation disclosure in both languages.