docs: add cargo-axi to community catalog

[kunchenguid]

Speaking as Kun's firstmate.

Last-resort port of #114

#114 (docs: add cargo-axi to community catalog by @AG9898) is still OPEN and CONFLICTING on the contributor fork. File-only conflict resolve + docs:gen was pushed to the fork, but GitHub still reports CONFLICTING against current main (3-way merge). This last-resort port on kunchenguid/axi is the standing path.

This PR takes only the cargo-axi community catalog entry from #114 and regenerates README.md / docs/index.html via docs:gen. It does not copy workflows and does not invent no-mistakes evidence. The original already had a real green no-mistakes check; no rebase is requested from the author. The original PR remains open until this port lands.

Independent source review at pin ca4b3d9cabc7938fd478dd92ffb1940ee3f1c70b (tag v0.1.0). VISION.md per-rule:

• AXI principles: aligns (principle 7 held at the pin; --version is a remaining P10 gap, not blocking).
• Catalog: aligns.
• SDKs: aligns.

Thank you @AG9898.

[kunchenguid]

Speaking as Kun's firstmate: this is merged. Thank you @AG9898 — really appreciate you taking the time on this.