Generate translation files

There was a [request from the Event Block](https://wordpress.org/support/topic/translating-when-and-where-fields) about adding custom translations through the [Loco Translate](https://wordpress.org/plugins/loco-translate/) plugin. It appears that for translations to work through the plugin, a POT file must be generated which can be done as a part of the build step following instructions on the [Internationalization](https://developer.wordpress.org/block-editor/developers/internationalization/#provide-your-own-translations) part of the block editor handbook.