add name-free interaction

https://developer.amazon.com/en-US/docs/alexa/custom-skills/understand-name-free-interaction-for-custom-skills.html should allow users to ask if there's a snow emergency without using the wake word

Start by reading the linked Alexa documentation on name-free interaction, then inspect the repository's Alexa skill entry points to understand how requests are handled. The work is done when users can ask whether there is a snow emergency without using the wake word, subject to the platform behavior described in the documentation.

Written by the indexing model from the issue text.