feat: Add flag to disable the replaceState in scrollspy

[arnoldknott]

Discussion

Adresses #130

Functionality

Allows turning off the replaceState through a flag in scrollspy to mitigate warning in Svelte.

Changes made

I have added the option [--scrollspy-replace-history:false] as a flag similar to [--scrollspy-offset], and an if-statement, to skip the replaceState().

A working code for the scrollspy area then looks like this, when this new flag is in use - here combined with the offset-flag:

<div id="scrollspy" data-scrollspy="#scrollspy" data-scrollspy-scrollable-parent="#scrollspy-scrollable-parent" class="[...] [--scrollspy-offset:170] [--scrollspy-replace-history:false] sm:[--scrollspy-offset:100]" >
....
</div>

Potential enhancements

Further enhancements of this could be to add an option for pushState and scrolling to the correct destination after a following popState.

Please let me know, what you think - I'd be happy to make changes and adopt to your thoughts. 🙏