Multi-target support

While using this specification, we imperatively found out that it may become too verbose. Being able to define an array of targets would greatly simplify some use cases. Was it considered?

Example

Current state:

overlay: 1.1.0
info:
  title: Targeted Overlay
  version: 1.0.0
actions:
  - target: $.paths['/foo'].get.description
    update: This is the updated description
  - target: $.paths['/bar'].get.description
    update: This is the updated description
  - target: $.paths['/baz'].get.description
    update: This is the updated description

Possible variation:

overlay: 1.1.0
info:
  title: Targeted Overlay
  version: 1.0.0
actions:
  - target:
    - $.paths['/foo'].get.description
    - $.paths['/bar'].get.description
    - $.paths['/baz'].get.description
    update: This is the new description

Disclaimer: the example above is intentionally artificial for simplicity reasons.

Start with issue #267's current and proposed YAML examples, then review the existing Overlay action and target rules to determine whether one action may contain an array of targets. Done means an agreed specification change or explicit decision, with the syntax and validation behavior documented; no file or test is named in the issue.