feat: Update Newsletter Section Content for Better Engagement

[akshay0611]

Summary: This PR updates the content of the newsletter section to improve clarity, relevance, and engagement. The changes aim to better communicate the value of subscribing to the newsletter for weekly insights and updates.

Changes Made:

• Rewrote the content of <p class="section-subtitle"> to emphasize joining the newsletter.
• Updated <h2 class="h2 section-title"> to highlight weekly insights and updates.
• Improved alt text for the image to enhance accessibility and SEO.
• Ensured alignment with existing CSS styles and framework conventions.

Testing:

• Verified responsiveness across different screen sizes.
• Ensured proper rendering of the newsletter section and its content.

Related Issue: Closes #9