Possible issue with missing type declaration files for ESM exports

Hi, this is possibly user error, but a recent routine release of my lib react-flip-toolkit broke type declarations-- a user filed an issue here and when I view the analysis on this page I see that types are not found.

After digging around for a bit, it seems possible based on my reading of this explanation that we need to package an index.d.mts alongside the index.d.ts automatically generated by microbundle.