Automations - Improve UI to be friendly to multi-line Liquid in yaml

When building custom email automations, it's quite likely you're going to want to do some multiline Liquid in yaml, for example to change the "to" field dynamically based on submitted data.

In yaml, to make the data multi-line you need to start with a ">" or "|", start a new line and indent with two spaces.

This works fine, and Siteglide doesn't overwrite the multiline syntax if you add via CLI, but in the Admin UI it displays as a single line field making it hard to read / write and the developer is not confident that it will work.

I think an achievable suggestion would be to make these fields multiline by default in the UI and automatically add the yaml multiline syntax.