Add docs for setting up cloud provider provider section

[thepalbi]

This PR adapts the docs generator template to include instructions on how to setup the Cloud Provider terraoform provider section. It instructs how to create the api token and correct hostname.

For setting up the hostname, the UI is super misleading as the cluserSlug is not shown but rather something like friendly names:

The easiest solution is call Grafana's API with the same token the user has to create, as follows:

➜  work curl -sH "Authorization: Bearer $(cat ~/work/personal-stack-token.txt)" "https://grafana.com/api/instances"|jq '[.items[]|{stackName: .slug, clusterName:.clusterSlug, cloudProviderAPIURL: "https://cloud-provider-api-\(.clusterSlug).grafana.net"}]'
[
  {
    "stackName": "herokublogpost",
    "clusterName": "prod-us-central-0",
    "cloudProviderAPIURL": "https://cloud-provider-api-prod-us-central-0.grafana.net"
  },
  {
    "stackName": "pablobalbitest",
    "clusterName": "prod-us-east-0",
    "cloudProviderAPIURL": "https://cloud-provider-api-prod-us-east-0.grafana.net"
  },
  {
    "stackName": "palbiuscentral2",
    "clusterName": "us-central2",
    "cloudProviderAPIURL": "https://cloud-provider-api-us-central2.grafana.net"
  }
]

Also, adjusts the examples so that they are the easiest possible to read.

Solves https://github.com/grafana/grafana-csp-app/issues/140

[github-actions]

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