Add a scroll to top button

[vivitt]

Fixes

• Fixes [Feature] Add a scroll back to top button #168 by Riddhi9570

Description

Included a link element in the listing layout to allow users to quickly navigate to the top of the page.

This element targets an anchor tag in the page header and is styled to match the existing 'download resource' button's styling.

JavaScript functionality has been implemented in scroll.js to dynamically display the 'scroll to top' button only when the scroll position is greater than 400px.

Note that, in order to avoid duplication in style.css, the shared styles for '.downloadbutton' and '.backtotopbutton' were extracted into a new CSS class '.button'.

Screenshots

Before

After

Checklist

• My pull request has a descriptive title (not a vague title like Update index.md).
• My pull request targets the default branch of the repository (main or master).
• My commit messages follow best practices.
• My code follows the established code style of the repository.
• I added or updated tests for the changes I made (if applicable).
• I added or updated documentation (if applicable).
• I tried running the project locally and verified that there are no
  visible errors.

Developer Certificate of Origin

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Developer Certificate of Origin

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[possumbilities]

Closing this and moving the area of focus to Vocabulary.

• [Feature] Add a scroll-to-top element to UX for longer page contexts vocabulary#54