Stable documentation links

Ensure all documentation links are stable, consistent, and correctly targeted to improve navigation and long-term maintainability:

1. Use stable references: Always link to stable release tags or specific commit hashes rather than volatile branches like master or main: ```diff
   • kubectl apply -f https://raw.githubusercontent.com/ray-project/kuberay/refs/heads/master/ray-operator/config/samples/vllm/ray-service.vllm.yaml
   • kubectl apply -f https://raw.githubusercontent.com/ray-project/kuberay/vX.Y.Z/ray-operator/config/samples/vllm/ray-service.vllm.yaml ```
2. Maintain consistent file extensions: Use consistent file extensions (.md or .html) throughout documentation links, preferring .md for markdown source files: ```diff
   • See also: full example
   • See also: full example ```

3. Verify relative paths: Ensure relative paths resolve correctly within the documentation structure by testing links in the built documentation.

4. Use standardized link syntax: Follow project conventions for link formatting, such as using autolink syntax: ```diff
   • While ongoing efforts like #17419
   • While ongoing efforts like <gh-issue:17419> ```
5. Target specific sections: When linking to pages with tabs or complex navigation, link directly to the specific section or tab to improve user experience.