Create cluster configuration section and API docs section

[ry4nz]

SME - @ranyodh

API - MkeConfig

In MKE3, configuration can be updated using the TOML config file which can be accessed from an API endpoints (/api/ucp/config-toml). To apply a change, a user can update this config file, and then upload it on the cluster at this endpoint: /api/ucp/config-toml

In MKE4, configuration is specified using a k8s custom resource named “MkeConfig”. It is a YAML file, with structure very similar to existing MKE3’s TOML file. To apply a change, a user can update MkeConfig, and then use mkectl apply -f .

API - HTTP API
MKE3 has a number of HTTP API endpoints to manage the cluster, manage users, tune etcd etc. Most of these APIs are not available in MKE4.0

In MKE4.0, following HTTP API is available:
Standard Kubernetes HTTP API (at /api and /apis)
User Management (add/edit/delete Users) at (/auth/users)
Prometheus metrics (at /api/v1/namespaces/mke/services/monitoring-kube-prometheus-prometheus:http-web/proxy/api/v1/query_range)