Provide responsive table functionality

We need this for Web Fundamentals. Our current behaviour is to turn tables into a stacked list, but open to other good solutions. We include a data-th element with each table cell that provides the cell title.

See the table in [this file](https://github.com/google/WebFundamentals/blob/material-branch/src/content/en/fundamentals/design-and-ui/input/forms/label-and-name-inputs.markdown) as an example.