feat(templates): add pluggable template system with packs, catalog, resolver, and CLI commands

Co-authored-by: mnriem <15701806+mnriem@users.noreply.github.com>

templates/template/README.md

@@ -0,0 +1,49 @@
+# My Template Pack
+
+A custom template pack for Spec Kit.
+
+## Overview
+
+This template pack provides customized artifact templates for your development workflow.
+
+## Templates Included
+
+| Template | Type | Description |
+|----------|------|-------------|
+| `spec-template` | artifact | Custom feature specification template |
+
+## Installation
+
+```bash
+# Install from local directory (during development)
+specify template add --dev /path/to/this/directory
+
+# Install from catalog (after publishing)
+specify template add my-template-pack
+```
+
+## Usage
+
+Once installed, templates are automatically resolved by the Spec Kit scripts.
+When you run `specify specify` or create a new feature, your custom templates
+will be used instead of the core defaults.
+
+## Template Types
+
+- **artifact** — Document scaffolds (spec.md, plan.md, tasks.md, etc.)
+- **command** — AI agent prompts (the files in `.claude/commands/`, etc.)
+- **script** — Custom scripts that replace core scripts
+
+## Development
+
+1. Edit templates in the `templates/` directory
+2. Test with: `specify template add --dev .`
+3. Verify with: `specify template resolve spec-template`
+
+## Publishing
+
+See the [Template Publishing Guide](../../docs/TEMPLATE-PUBLISHING-GUIDE.md) for details.
+
+## License
+
+MIT