Beginning of auth and auth
Adds grant screen requirements and examples
Adds client_secret_alg_supported

oada-configuration needs a way to say what type of client secrets signing is allowed.
Adds client secret documentation
Adds examples of OAuth 2.0 implicit and code flows
Adds OpenID Connect implicit flow
Adds OpenID Connect code flow
Fixes some typos
Adds Authentication and Authorization to README
Adds oada-client-discovery WK document
Fixes JSON typo
Merge pull request #2 from OADA/auth_and_auth

Auth and auth