feat:better styling for thumb/track radius

[kantakshay]

Fixes Issue

My PR closes #467

👨‍💻 Changes proposed(What did you do ?)

1) first of all, I changed the styles of the checkbox as per the new design. 2) Added + and - buttons beside the input element. 3) styled them so they look good. 4) Implemented function to the + and - buttons so they can add or subtract the values of input elements. 5) for the function implementation, I made changes in the input-range.ts and getElement.ts files

✔️ Check List (Check all the applicable boxes)

• [x] My code follows the code style of this project.
• [x] This PR does not contain plagiarized content.
• [x] The title and description of the PR is clear and explains the approach.

Note to reviewers

📷 Screenshots

[Dun-sin]

@kantakshay stop closing and opening PRs, you can edit a PR