Add YAML frontmatter to all skills for automatic discovery

Skills require YAML frontmatter with name and description fields
for Claude Code to automatically discover and load them. Added
frontmatter to all five skill files:
- gitea: CLI for issues, PRs, and repository management
- code-review: Guidelines for reviewing code changes
- issue-writing: How to write clear, actionable issues
- backlog-grooming: Review and improve existing issues
- roadmap-planning: Plan features and create issues

Closes #12

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

skills/backlog-grooming/SKILL.md

@@ -1,3 +1,8 @@
+---
+name: backlog-grooming
+description: How to review and improve existing issues for clarity and actionability
+---
+
 # Backlog Grooming
 
 How to review and improve existing issues.

skills/code-review/SKILL.md

@@ -1,3 +1,8 @@
+---
+name: code-review
+description: Guidelines and templates for reviewing code changes in pull requests
+---
+
 # Code Review
 
 Guidelines for reviewing code changes in pull requests.

skills/gitea/SKILL.md

@@ -1,3 +1,8 @@
+---
+name: gitea
+description: Gitea CLI (tea) for issues, pull requests, and repository management
+---
+
 # Gitea CLI (tea)
 
 Command-line interface for interacting with Gitea repositories.

skills/issue-writing/SKILL.md

@@ -1,3 +1,8 @@
+---
+name: issue-writing
+description: How to write clear, actionable issues with proper structure and acceptance criteria
+---
+
 # Issue Writing
 
 How to write clear, actionable issues.

skills/roadmap-planning/SKILL.md

@@ -1,3 +1,8 @@
+---
+name: roadmap-planning
+description: How to plan features and create issues for implementation
+---
+
 # Roadmap Planning
 
 How to plan features and create issues for implementation.