Demo/Examples Enhancement: Add Dynamic Chart PDF export example

[KARLE-ATHARVA]

📄 Hacktoberfest Demo/Examples Enhancement

This PR adds a practical dynamic chart PDF export example under examples/dynamic_charts/:

1. Dynamic Bar Chart Example – demonstrates how to generate a bar chart using Chart.js.
2. PDF Export Example – demonstrates how to convert the chart to an image and embed it into a PDF using jsPDF, including a title and current date.

✅ Why this is helpful

• Provides a real-world workflow for exporting visual data to PDFs.
• Examples are self-contained, beginner-friendly, and ready to copy-paste into projects.
• Organized under dynamic_charts/ to keep dynamic examples separate from static chart demos.
• Enables developers to create reports, dashboards, or educational charts effortlessly in the browser.

Looking forward to feedback from maintainers! 🙌