I think it is better to enumerate the list of text input types here as in the other cases, otherwise a `pure-stacked-form` requires `LABEL` elements in order to stack.

I've submitted a PR that does this and also removes the block formatting from `BUTTON` in `forms-r`, which is required to complete the normalization between `BUTTON` and `INPUT` type buttons:
https://github.com/tilomitra/pure/pull/6