feat(useWindowScroll): allow rewriting back to scroll

[nothing-sy]

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⚠️ Slowing down new functions

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As the VueUse audience continues to grow, we have been inundated with an overwhelming number of feature requests and pull requests. As a result, maintaining the project has become increasingly challenging and has stretched our capacity to its limits. As such, in the near future, we may need to slow down our acceptance of new features and prioritize the stability and quality of existing functions. Please note that new features for VueUse may not be accepted at this time. If you have any new ideas, we suggest that you first incorporate them into your own codebase, iterate on them to suit your needs, and assess their generalizability. If you strongly believe that your ideas are beneficial to the community, you may submit a pull request along with your use cases, and we would be happy to review and discuss them. Thank you for your understanding.

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Description

Add x,y computed for scrolling

Additional context

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🤖 Generated by Copilot at 2d15313

Added smooth scrolling feature to useWindowScroll function and demo. Users can now customize the scroll behavior and control the window scroll position by assigning to the reactive values returned by the function. Updated the documentation to reflect the new feature.

🤖 Generated by Copilot at 2d15313

• Add and export UseWindowScrollOptions interface to allow specifying scroll behavior (link)
• Update useWindowScroll function to accept UseWindowScrollOptions and use computed properties for x and y values (link, link)
• Use scrollTo method in computed setters to perform scrolling with the given behavior (link)
• Add buttons to demo.vue template to trigger scrolling on x and y axes by modifying reactive values (link)
• Call useWindowScroll with smooth scroll behavior in demo.vue script (link)
• Update usage section in index.md to show how to set scroll position programmatically (link)