documentation update

[sdarwin]

Hi,
The marketplace 1-Click Apps are really neat!
Here's a suggestion about something which was briefly confusing on this page: https://marketplace.digitalocean.com/apps/cert-manager, and similar pages.

After this text:

"""
You can always inspect all the available options, as well as the default values for the cert-manager Helm chart by running below command:

helm show values jetstack/cert-manager --version 1.13.3

"""

Add this:

"""
The custom values applied to the release can be found in values.yaml, or by running the following command:

helm get values cert-manager -n cert-manager

"""

The reason why this is important, is the next sentence says "After tweaking the Helm values file". That means the user might be customizing their own local values file, and applying it with Helm. If anything, they ought to start out with the existing customized values, and proceed from there. By including the additional suggested text, it will assist them in understand what's already in-place. Otherwise, the previous customized values will be dropped, right?