Implement a possible check function to determine whether or not mkcert has been run before

[echoboomer]

It would be great if there were some sort of -check flag to return whether or not a system/other trust store has been created already. In cases where mkcert is a dependency of some other platform or service, advising users to stop and run mkcert -install if the trust store either does or does not exist would be ideal without needing to run -install.

[harelzar]

mkcert --version