Update README with Skills.sh installation guide (#14)

Added installation instructions for Skills.sh to the README and moved
how it works before the installation process.

Author: fellyph

README.md

@@ -38,8 +38,68 @@ Agent Skills solve this by giving AI assistants **expert-level WordPress knowled
 | **wp-plugin-directory-guidelines** | WordPress Plugin Directory Guidelines |
 | **blueprint** | WordPress Playground Blueprints for declarative Playground environment setup |
 
+## How It Works
+
+Each skill is a self-contained folder with instructions, references, and optional scripts:
+
+```
+skills/wp-block-development/
+├── SKILL.md              # Main instructions (when to use, procedure, verification)
+├── references/           # Deep-dive docs on specific topics
+│   ├── block-json.md
+│   ├── deprecations.md
+│   └── ...
+└── scripts/              # Deterministic helpers (detection, validation)
+    └── list_blocks.mjs
+```
+
+When you ask your AI assistant to work on WordPress code, it reads these skills and follows the documented procedures rather than guessing.
+
+
+## Global vs. Project Scope
+
+Skills can be installed in two scopes:
+
+**Global** — installed in your home directory (e.g. `~/.claude/skills/`, `~/.cursor/skills/`).
+- Available across **all** your projects automatically.
+- Best for individual developers who want WordPress knowledge in every repo.
+
+**Project** — installed inside a repository (e.g. `.claude/skills/`, `.github/skills/`, `.cursor/skills/`).
+- Available only within **that specific project**.
+- Can be committed to version control so the entire team benefits.
+
+You can use both at the same time. When a skill exists in both scopes, the project-level version is used.
+
 ## Quick Start
 
+The fastest way to install a skill is with a single command:
+
+```bash
+npx skills add WordPress/agent-skills --skill wp-plugin-development
+```
+
+To see all available skills:
+
+```bash
+npx skills add WordPress/agent-skills --list
+```
+
+To install multiple skills at once:
+
+```bash
+npx skills add WordPress/agent-skills --skill wp-plugin-development wp-abilities-api wp-playground
+```
+
+#### Choosing a scope
+
+`npx skills add` asks to choose the skill **project-scoped**, selecting the local scope on which the skills are installed in the local project; it can be stored at the repository (e.g. `.claude/skills/`, `.cursor/skills/`) — so the skills can be committed to version control and shared with your team.
+
+Installing **globally** makes the skill available to your user (across **all** your projects). Adding the `-g` / `--global` flag, it will install your skill with global scope:
+
+```bash
+npx skills add WordPress/agent-skills --skill wp-plugin-development --global
+```
+
 ### Install globally for Claude Code
 
 ```bash
@@ -104,23 +164,6 @@ node shared/scripts/skillpack-install.mjs --dest=../my-repo --targets=claude,cur
 
 Copy any skill folder from `skills/` into your project's instructions directory for your AI assistant.
 
-## How It Works
-
-Each skill contains:
-
-```
-skills/wp-block-development/
-├── SKILL.md              # Main instructions (when to use, procedure, verification)
-├── references/           # Deep-dive docs on specific topics
-│   ├── block-json.md
-│   ├── deprecations.md
-│   └── ...
-└── scripts/              # Deterministic helpers (detection, validation)
-    └── list_blocks.mjs
-```
-
-When you ask your AI assistant to work on WordPress code, it reads these skills and follows the documented procedures rather than guessing.
-
 ## Compatibility
 
 - **WordPress 6.9+** (PHP 7.2.24+)