Add TSDoc documentation

[dcastil]

Just stumbled across https://tsdocs.dev/docs/tailwind-merge and thought that it would be nice to have more inline documentation for tailwind-merge in the editor with TSDoc.

I could add some base docs with links to the versioned full documentation on GitHub in TS Docs. That means, those links would need to be partially autogenerated.

• TSDoc documentation: https://tsdoc.org