feat: Update doctors listing content for better relevance

[akshay0611]

Summary: This PR updates the content of the "Doctors Listing" section to improve clarity, relevance, and engagement. The changes aim to better communicate the value proposition of Doclab's medical specialties.

Changes Made:

• Rewrote the content of <p class="card-text"> for each specialty to highlight its unique benefits.
• Updated alt texts for icons to improve accessibility.
• Fixed a typo in the section subtitle ("Listig" → "Listing").
• Ensured alignment with existing CSS styles and framework conventions.

Testing:

• Verified responsiveness across different screen sizes.
• Ensured proper rendering of the doctors listing cards and their content.

Related Issue: Closes #7