* Add a prop to turn on “single choice” mode
* Create new ProductControl to select a single product
* Remove align from shared attributes
This is given to us by default for using supports.align
* Add Featured Product block
* Fix spelling mistake & copy-paste issue
* Fix lint warning
* Add featured product script to build process, register block in PHP
This lets us use the functionality of `register_block_type` to automatically enqueue the scripts and styles used by blocks in the editor, and eventually, styles on the frontend as well. Also adds cssnano to minify our CSS.