message: docs: provide config option for openid-connect provider
diff: @@ -177,10 +177,29 @@ from custom_sso_security_manager import CustomSsoSecurityManager
  CUSTOM_SECURITY_MANAGER = CustomSsoSecurityManager
  ```
  -Notice that the redirect URL will be `https://<superset-webserver>/oauth-authorized/<provider-name>`
  +**Notes**
  +
  +- The redirect URL will be `https://<superset-webserver>/oauth-authorized/<provider-name>`
  When configuring an OAuth2 authorization provider if needed. For instance, the redirect URL will
  be `https://<superset-webserver>/oauth-authorized/egaSSO` for the above configuration.
  +- If an OAuth2 authorization server supports OpenID Connect 1.0, you could configure its configuration
  + document URL only without providing `api_base_url`, `access_token_url`, `authorize_url` and other
  + required options like user info endpoint, jwks uri etc. For instance:
  + ```python
  + OAUTH_PROVIDERS = [
  + { 'name':'egaSSO',
  + 'token_key':'access_token', # Name of the token in the response of access_token_url
  + 'icon':'fa-address-card', # Icon for the provider
  + 'remote_app': {
  + 'client_id':'myClientId', # Client Id (Identify Superset application)
  + 'client_secret':'MySecret', # Secret for this Client Id (Identify Superset application)
  + 'server_metadata_url': 'https://myAuthorizationServer/.well-known/openid-configuration'
  + }
  + }
  + ]
  + ```
  +
  ### Feature Flags
  To support a diverse set of users, Superset has some features that are not enabled by default. For
  