add `include` in the action schema

[shazron]

what:

• https://github.com/adobe/aio-cli/issues/207
• (tests) https://github.com/apache/openwhisk-wskdeploy/blob/8e4a79926039612c5242f06942c3382919acc021/tests/src/integration/zipactionwithinclude/manifest.yml

where: https://github.com/adobe/aio-cli-lib-app-config/blob/9a1fcd14cb242b26a9c2ad7be728f44b9a28e363/schema/app.config.yaml.schema.json#L128

[aiojbot]

JIRA issue created: https://jira.corp.adobe.com/browse/ACNA-2881