docs: Update README with Enhanced Features, Screenshots, and GSSOC Contribution Guide

[arunvijo]

This PR updates the README.md to:

• Add newly released and upcoming features for TalkHeal
• Include detailed in-app conversation examples and user flows
• Add and organize screenshots for better visual onboarding
• Improve Markdown styling and badge layout for clarity
• Update contribution guidelines, including steps for GSSOC'25 newcomers
• Add direct instructions for bug reporting and feature requests

These changes address Issue #28 (Keep README Updated & Stylish - Contributor-Friendly Issue) and make it easier for new contributors and GSSOC participants to get started.

Please review and suggest any additional enhancements for the README!

[eccentriccoder01]

@arunvijo Thanks for the contribution, it's a good start! However, there are a few things to address:

• You've kept the screenshot from the older version of the app instead of using one from the latest deployment at https://talkheal.streamlit.app/. Also, the screenshot was added twice by mistake, and it's placed where the badges should be in the Live Demo section.
• The text changes made are quite minimal, and there's no significant improvement in structure or styling. Also, there's no need to move the badges from their original place.

I'd suggest:

• Reviewing the recently merged PRs to reflect the latest functionalities and adding enhancements to the README.
• A fresh screenshot from the current deployment (to replace the existing one in the screenshots section)
• Visually engaging elements like GIFs, a contributors section (feel free to include yourself!), and cleaner formatting
• Also I have assigned you the issue (Keep README Updated & Stylish - Contributor-Friendly Issue #28), so make sure to link this PR to the issue.

Looking forward to your updated PR!

[Sruthi-sruzz]

@arunvijo hello ,iam sruthi ,GSSoC contributor ,could you please asssign this issue to me.

[eccentriccoder01]

This is s pull request @Sruthi-sruzz, not an issue!
Feel free to check out unassigned issues in the issues section or open your own, we will review them and duly assign you :)