3730 update api key - doc update  (#3731)
3730 update api key - doc update  (#3731)

* updated doc for added update_api_key / update_usage_plan feature

* updated doc for added update_api_key / update_usage_plan feature

Co-authored-by: rajinder saini <6cedfeece6c7c8b6c56b3349cb4d8391c0943f39@c02vt5k2htd6.corp.climate.com>
william-richard/moto,william-richard/moto,spulec/moto,spulec/moto,spulec/moto,william-richard/moto,spulec/moto,william-richard/moto,william-richard/moto,spulec/moto,william-richard/moto,spulec/moto