add feature classnames change after name props change

[MFrozenM]

I closed the previous PR and open a new one with createMemo instead of createEffect and a few other changes.

Thanks to @thetarnav

[ryansolid]

Thanks to you both

[clementmas]

@MFrozenM, I think removing mergeProps created this issue #22

[MFrozenM]

@clementmas Does your code with tailwind work in previous versions of the library?