Update the "server"-section to align with other CAMARA specifications

[maxl2287]

Current description

servers:
  - url: "{apiRoot}/{basePath}"
    variables:
      apiRoot:
        default: http://localhost:9091
        description: API root
      basePath:
        default: qod/v0
        description: Base path for the QoD API

Expected behavior

servers:
  - url: "{apiRoot}/qod/v0"
    variables:
      apiRoot:
        default: http://localhost:9091
        description: API root

Additional context
Related to camaraproject/NumberVerification#77