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/sprite-animation/SKILL.md

@@ -20,7 +20,7 @@ triggers:
   - "精灵图"
   - "像素动画"
   - "复古动画"
-ocd:
+od:
   mode: prototype
   platform: desktop
   scenario: marketing
@@ -73,7 +73,7 @@ display, looping CSS animations, kinetic Japanese / English display type.
    - All animations use `@keyframes` + `animation: ... infinite`.
    - Stage uses a fixed canvas ratio (e.g. 16:9 letterboxed) so the loop
      reads as a single frame from a video.
-   - `data-ocd-id` on stage, year, sprite, caption, and tick ribbon.
+   - `data-od-id` on stage, year, sprite, caption, and tick ribbon.
 8. **Self-check**:
    - The page is one cohesive scene, not a collage. The eye lands on the
      year first, then the sprite, then the caption.