add a pre-flight check to ensure that all the dependencies needed are there

[viankakrisna]

Steps to Reproduce:

run npx create-wp-site in a machine without docker-compose command available

Expected Behavior:

1. create-wp-site fails gracefully and point the user to setup docker-compose on their machine it's not available
2. create-wp-site does not leave the site URL in /etc/hosts

Actual Behavior

1. create-wp-site still runs and create the project (there are some references of docker-compose is not available, but it still runs and congratulate the user)
2. the site URL is still in the /etc/hosts