Supplement SKILL.md to assist AI in completing tasks better

## Enhancement Task

> https://agentskills.io/home

### Overview

A simple, open format for giving agents new capabilities and expertise.

Agent Skills are folders of instructions, scripts, and resources that agents can discover and use to do things more accurately and efficiently.

### Why Agent Skills?
Agents are increasingly capable, but often don’t have the context they need to do real work reliably. Skills solve this by giving agents access to procedural knowledge and company-, team-, and user-specific context they can load on demand. Agents with access to a set of skills can extend their capabilities based on the task they’re working on.

- For skill authors: Build capabilities once and deploy them across multiple agent products.
- For compatible agents: Support for skills lets end users give agents new capabilities out of the box.
- For teams and enterprises: Capture organizational knowledge in portable, version-controlled packages.

### What can Agent Skills enable?

- Domain expertise: Package specialized knowledge into reusable instructions, from legal review processes to data analysis pipelines.
- New capabilities: Give agents new capabilities (e.g. creating presentations, building MCP servers, analyzing datasets).
- Repeatable workflows: Turn multi-step tasks into consistent and auditable workflows.
- Interoperability: Reuse the same skill across different skills-compatible agent products.

### Which SKILL does PD need

- Various complex deployment approaches
- How to use tiup cluster to deploy a cluster, verify its functionality, and when it is necessary to use tiup cluster for validation
- (Commonly used) How to use tiup playground to deploy a simple test cluster, verify its functionality, and when it is necessary to use tiup cluster for validation
- How to use TiDB Operator to deploy a cluster or a microservice-based cluster, and in which scenarios it should be used

- Various usages of pd-ctl

- How to use pd-xxx-bench to test specific interfaces

- And so on (to be supplemented)