Add documentation about distributing the Certificate CA generated by Pulp Installer
The user needs to be provided with information about 3 scenarios:
Pulp Installer generated a CA certificate, created an SSL certificate that is signed by that CA, and configured .
Pulp Installer user provided an SSL certificate and the Pulp Installer configured the web server to use that certificate.
Pulp Installer user used a role to request a LetsEncrypt SSL certificate or from some other acme protocol compatible service. The installer then configured the web server to use that SSL certificate.