Mercure extension for ddev

This extension is based on dunglas/mercures implementation.

To install it, for DDEV v1.23.5 or above run

ddev add-on get Rindula/ddev-mercure

For earlier versions of DDEV run

ddev get Rindula/ddev-mercure

The mercurehost will be available under mercure.${DDEV_HOSTNAME}. So for example.ddev.site the url will be mercure.example.ddev.site. From inside the web container, you can reach mercure under http://mercure:3000.