feat: Update about section content for better relevance

[akshay0611]

Summary:
This PR updates the content of the "About Us" section to improve clarity, relevance, and engagement. The changes aim to better communicate the value proposition of Doclab as a trusted healthcare provider.

Changes Made:

• Rewrote the content of <p class="section-text"> to introduce the hospital's team and values.
• Updated <p class="tab-text"> to reflect the hospital's vision.
• Rewrote list items to highlight key strengths and commitments.
• Improved the alt text for the banner image for better accessibility.
• Ensured alignment with existing CSS styles and framework conventions.

Testing:

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

Related Issue:
Closes #5