Query mkcert installation status

[mattrussell-sonocent]

We use mkcert as part of our local development environment (it's a lovely tool, thanks!), and we also have some diagnostic scripts developers can run to verify their local environment is configured correctly, and suggest steps to fix if not. One check we'd quite like to add is to verify that mkcert -install has been run (because occasionally developers will overlook this step). Is it possible to query the installation status via the command line tool?