feat: add clean timeline example without swimlanes

Created example-1 directory with minimalist timeline template that uses vertical anchor lines to connect items to a central horizontal timeline bar. This demonstrates an alternative visualization style without the swimlane-based layout.

Features:
- Clean template-v2.svg with vertical dashed anchor lines
- Central horizontal timeline bar at y=190
- Items positioned above/below timeline with circle markers
- Minimal styling with clean typography
- 12-month timeline configuration
- Sample data with milestones, development, and research items
- Uses standard ITEM_ID and ITEM_TITLE placeholders

Files:
- template-v2.svg: Clean SVG template with anchor line design
- project.json: Configuration for 12-month timeline
- sample.csv: Sample timeline data with 14 items
- style.css: Minimal CSS styling
- output.svg: Generated timeline (for reference)

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

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

example-1/project.json

@@ -0,0 +1,16 @@
+{
+  "name": "Clean Timeline Example",
+  "description": "Minimalist timeline visualization without swimlanes, using vertical anchor lines to connect items to a central timeline bar",
+  "dataSource": "sample.csv",
+  "stylesheet": "style.css",
+  "svgTemplate": "template-v2.svg",
+  "settings": {
+    "timelineMonths": 12
+  },
+  "fieldMapping": {
+    "id": "ID",
+    "title": "Title",
+    "lane": "Category",
+    "due": ["Due Date"]
+  }
+}