Add `description` fields to all OpenAPI schemas

[antoineco]

We want users to be able to discover APIs (custom objects) using kubectl explain, therefore we need to mirror our APIs' Godocs to the OpenAPI schemas contained inside CRDs.

• [x] awscloudwatch

  314

• [x] awscloudwatchlogs

  315

• [x] awscodecommit

  316

• [x] awsdynamodb

  317

• [x] awskinesis

  318

• [x] awsperformanceinsights

  322

• [x] awss3

  319

• [x] awssns

  321

• [x] awssqs

  320

• [x] awscognitoidentity

  324

• [x] awscognitouserpool

  323