Remarks came up during testing of 7.13.0-alpha5:

• Add missing 404 code for `/process-definition/key/{key}/start` in case you provide an unexisting key.

• Remove quotes from example's summaries to have consistency, expected:
  • "summary": "POST /deployment/anDeploymentId/redeploy"
• Improve example's summary of task complete:
  • it should state clearly what's the difference between the examples - with/without variables in return
  • check for other similar cases