fixed the layout of the landing page i.e. added bootstrap elements to index.html file in the project directory

[avinashsinghpal]

📌 What does this PR do?

improves the layout of the landing page, if considered then I will improve the layout of the whole website and properly manage all the files in the project directory.

Related Issue

Fixes #371 #381

🔧 Type of Change

• Bug fix (non-breaking change)
• New feature
• Breaking change
• Documentation update

✅ How Has This Been Tested?

yes tested

Include environment details (Operating System, browser, Node version, etc.)

📸 Screenshots (if UI changed)

📊 Impact / Performance

makes the ui of landing page more clean and defined.

✅ Checklist

• I have followed the code style guidelines.
• I have self-reviewed my code.
• I have commented on complex parts of the code.
• I have updated or added documentation where necessary.
• All tests pass locally.
• No new warnings have been introduced.