[docs/quickstart] Create a 5-minute quick start path

[mesutoezdil]

Context

This issue is part of the HAMi v2.9.0 Documentation Revamp Plan (WS7 - Quick Start Redesign).

The current quick start covers installation, uninstall, and upgrade in detail (PR #181, #196, #197). What is still missing is a fast, opinionated path for a user who wants to get HAMi running in under 5 minutes without reading the full installation guide.

Before you start

Please reach out to the maintainers before picking this up:

• @rootsongjc (author, architecture decisions)
• @mesutoezdil (revamp reviewer, scope alignment)

This ensures your work aligns with the broader documentation direction and avoids rework.

Scope

Create docs/get-started/quick-path.md with the following structure:

• Prerequisites (minimal - only what is truly required)
• Single-command or two-command install path using Helm
• One minimal workload example that exercises GPU sharing
• Expected output so the user can verify success
• Link to full installation guide for users who need more control

Acceptance criteria

• A user with a running Kubernetes cluster can follow the guide and verify HAMi is working within 5-10 minutes
• No steps that require explanation of internals
• Add the page to sidebars.js under the get-started section
• Chinese translation is not required for the initial PR but is welcome

Notes

• No emoji in the document
• No first-person language
• Code blocks must have a language specifier (e.g., bash, yaml)
• All admonitions must use Docusaurus syntax (:::note, :::warning)
• DCO sign-off required on every commit (git commit -s)