Helm: Generate a README.md file containing the values parameters

[Sgitario]

Suggestion

Generate for each chart a README.md file including the table of the parameters: Name | Description | Default)

Example: https://github.com/jenkinsci/helm-charts/blob/main/charts/jenkins/VALUES_SUMMARY.md#jenkins

# Jenkins

## Configuration

The following tables list the configurable parameters of the Jenkins chart and their default values.

### Jenkins Controller

| Parameter                                   | Description                                                              | Default                                                              |
|---------------------------------------------|--------------------------------------------------------------------------|----------------------------------------------------------------------|
| `checkDeprecation`                          | Checks for deprecated values used                                        | `true`                                                               |
| `clusterZone`                               | Override the cluster name for FQDN resolving                             | `cluster.local`                                                      |
| `nameOverride`                              | Override the resource name prefix                                        | `jenkins`                                                            |

That will improve the readability of the chart generated when it will be published on a Helm repo like also its team's adoption by a project

2 tools currently exist to generate such tables but up to you to decide if you prefer to generate it part of this extension:

• https://github.com/bitnami-labs/readme-generator-for-helm/tree/main
• https://github.com/norwoodj/helm-docs/

[Sgitario]

#1174 is a prerequisite for this issue.