Refactor project name from "Open Claude Design" to "Open Design" (#1)

* Refactor project name from "Open Claude Design" to "Open Design"

- Updated project name in package.json, package-lock.json, and README files.
- Changed CLI commands and references from "ocd" to "od".
- Adjusted file structure references in documentation and code to reflect new naming conventions.
- Enhanced .gitignore to include new runtime data files.
- Updated metadata in LICENSE file to match new project name.

* Add contributing guidelines in English and Chinese

- Introduced CONTRIBUTING.md and CONTRIBUTING.zh-CN.md to provide clear instructions for contributors.
- Outlined contribution types, local setup instructions, and merging criteria for skills and design systems.
- Enhanced README files to reference the new contributing guidelines.

skills/docs-page/SKILL.md

@@ -11,7 +11,7 @@ triggers:
   - "tutorial"
   - "api reference"
   - "文档"
-ocd:
+od:
   mode: prototype
   platform: desktop
   scenario: engineering
@@ -48,7 +48,7 @@ Produce a single, three-column documentation page in one HTML file.
    - Code blocks: monospace token, soft surface fill, copy-button affordance
      (visual only — no JS needed).
    - Anchor IDs on every H2/H3 so the TOC links work.
-   - `data-ocd-id` on the nav, article, and TOC.
+   - `data-od-id` on the nav, article, and TOC.
 5. **Prose**: write at least 350 words of believable docs. Include at least
    one shell command, one code snippet (5–15 lines), one callout, one table.
 6. **Self-check**: