Add YAML multiline support

[kvaps]

Link PRO-Robotech/openapi-k8s-toolkit#171

Video:

Screen.Recording.2025-09-23.at.18.42.43.mov

Example resource:

kind: VirtualMachine
metadata:
  creationTimestamp: "2025-09-23T16:00:14Z"
  name: vm
  namespace: tenant-kvaps
  resourceVersion: "210202296"
  uid: 2d1ef591-fa2d-45ff-8d7a-e64496349b06
spec:
  cloudInit: |
    #cloud-config
    password: atomic
    chpasswd: { expire: False }
    ssh_pwauth: False
  cloudInitSeed: asdfsdf
  external: false
  externalMethod: PortList
  externalPorts:
  - 22
  gpus: []
  instanceProfile: ubuntu
  instanceType: u1.medium
  resources: {}
  running: true
  sshKeys: []
  systemDisk:
    image: ubuntu
    storage: 5Gi
    storageClass: replicated