Add new module template

[nabokihms]

Is your feature request related to a problem? Please describe.
The main problem is that it is hard to develop a new module from scratch. Users need to know what they can add and how it changes module behavior.

Describe the solution you'd like to see
It would be convenient to have an example/template of a new module. For example, let's look at the helm create command. By calling it, a user creates a new folder with every file which has a special meaning (Chart.yaml, values.yaml, etc.). Each file contains a description of what you can change in it.
Personally, I don't think we need a command, a folder that you can copy to create a new module should be enough.

Files which should be included in the template:

• README.md
• enable.sh
• hooks
• templates
• templates/openapi
• values.yaml
• .helmignore
• Chart.yaml (?)

Describe alternatives you've considered
I think the only alternative for users is to read docs and learn what features the addon-operator has. This is hard for newcomers, though.