Rephrase description of `provide-api-key` (#4654)
Rephrase description of `provide-api-key` (#4654)

Move the description of the default value of `provide-api-key` for new actions to the beginning of the description, before explaining the behavior when not specified in an existing action.

Related to [this suggestion](https://github.com/apache/openwhisk-catalog/issues/309#issuecomment-536907037).


rabbah/openwhisk,jasonpet/openwhisk,rabbah/openwhisk,jasonpet/openwhisk,markusthoemmes/openwhisk,openwhisk/openwhisk,jasonpet/openwhisk,RSulzmann/openwhisk,RSulzmann/openwhisk,jasonpet/openwhisk,jasonpet/openwhisk,style95/openwhisk,style95/openwhisk,RSulzmann/openwhisk,akrabat/openwhisk,jeremiaswerner/openwhisk,markusthoemmes/openwhisk,RSulzmann/openwhisk,jeremiaswerner/openwhisk,jeremiaswerner/openwhisk,akrabat/openwhisk,openwhisk/openwhisk,RSulzmann/openwhisk,jeremiaswerner/openwhisk,style95/openwhisk,style95/openwhisk,sven-lange-last/openwhisk,akrabat/openwhisk,akrabat/openwhisk,rabbah/openwhisk,rabbah/openwhisk,jeremiaswerner/openwhisk,openwhisk/openwhisk,jeremiaswerner/openwhisk,markusthoemmes/openwhisk,akrabat/openwhisk,markusthoemmes/openwhisk,sven-lange-last/openwhisk,style95/openwhisk,markusthoemmes/openwhisk,sven-lange-last/openwhisk,sven-lange-last/openwhisk,markusthoemmes/openwhisk,jasonpet/openwhisk,rabbah/openwhisk,jasonpet/openwhisk,openwhisk/openwhisk,style95/openwhisk,markusthoemmes/openwhisk,sven-lange-last/openwhisk,rabbah/openwhisk,akrabat/openwhisk,RSulzmann/openwhisk,RSulzmann/openwhisk,jeremiaswerner/openwhisk,style95/openwhisk,sven-lange-last/openwhisk,sven-lange-last/openwhisk,openwhisk/openwhisk,rabbah/openwhisk,openwhisk/openwhisk,markusthoemmes/openwhisk,akrabat/openwhisk