refactor: convert passive voice to imperative form in skill content

Convert "Understanding X enables creating Y" patterns to imperative
"Master X to create Y" form in 3 skills. Also convert second-person
"your" to definite article "the" in plugin-settings templates.

Skills updated:
- agent-development: line 11
- command-development: line 11
- plugin-structure: line 11
- plugin-settings: lines 296, 307, 371

Fixes #4

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: sjnims

plugins/plugin-dev/skills/agent-development/SKILL.md

@@ -8,7 +8,7 @@ version: 0.1.0
 
 ## Overview
 
-Agents are autonomous subprocesses that handle complex, multi-step tasks independently. Understanding agent structure, triggering conditions, and system prompt design enables creating powerful autonomous capabilities.
+Agents are autonomous subprocesses that handle complex, multi-step tasks independently. Master agent structure, triggering conditions, and system prompt design to create powerful autonomous capabilities.
 
 **Key concepts:**
 - Agents are FOR autonomous work, commands are FOR user-initiated actions

plugins/plugin-dev/skills/command-development/SKILL.md

@@ -8,7 +8,7 @@ version: 0.1.0
 
 ## Overview
 
-Slash commands are frequently-used prompts defined as Markdown files that Claude executes during interactive sessions. Understanding command structure, frontmatter options, and dynamic features enables creating powerful, reusable workflows.
+Slash commands are frequently-used prompts defined as Markdown files that Claude executes during interactive sessions. Master command structure, frontmatter options, and dynamic features to create powerful, reusable workflows.
 
 **Key concepts:**
 

plugins/plugin-dev/skills/plugin-settings/SKILL.md

@@ -293,7 +293,7 @@ Provide template in plugin README:
 ```markdown
 ## Configuration
 
-Create `.claude/my-plugin.local.md` in your project:
+Create `.claude/my-plugin.local.md` in the project:
 
 \`\`\`markdown
 ---
@@ -304,7 +304,7 @@ max_retries: 3
 
 # Plugin Configuration
 
-Your settings are active.
+Settings are active.
 \`\`\`
 
 After creating or editing, restart Claude Code for changes to take effect.
@@ -368,7 +368,7 @@ fi
 
 **Important:** Settings changes require Claude Code restart.
 
-Document in your README:
+Document in the plugin README:
 
 ```markdown
 ## Changing Settings

plugins/plugin-dev/skills/plugin-structure/SKILL.md

@@ -8,7 +8,7 @@ version: 0.1.0
 
 ## Overview
 
-Claude Code plugins follow a standardized directory structure with automatic component discovery. Understanding this structure enables creating well-organized, maintainable plugins that integrate seamlessly with Claude Code.
+Claude Code plugins follow a standardized directory structure with automatic component discovery. Master this structure to create well-organized, maintainable plugins that integrate seamlessly with Claude Code.
 
 **Key concepts:**