Update credential docstrings (Azure#18205)

Author: chlowell

sdk/identity/azure-identity/azure/identity/_credentials/browser.py

@@ -30,8 +30,6 @@ class InteractiveBrowserCredential(InteractiveCredential):
 
     :func:`~get_token` opens a browser to a login URL provided by Azure Active Directory and authenticates a user
     there with the authorization code flow, using PKCE (Proof Key for Code Exchange) internally to protect the code.
-    Azure Active Directory documentation describes the authentication flow in more detail:
-    https://docs.microsoft.com/azure/active-directory/develop/v1-protocols-oauth-code
 
     :keyword str authority: Authority of an Azure Active Directory endpoint, for example 'login.microsoftonline.com',
           the authority for Azure Public Cloud (which is the default). :class:`~azure.identity.AzureAuthorityHosts`

sdk/identity/azure-identity/azure/identity/_credentials/certificate.py

@@ -23,6 +23,9 @@ class CertificateCredential(ClientCredentialBase):
 
     The certificate must have an RSA private key, because this credential signs assertions using RS256.
 
+    See Azure Active Directory documentation for more information on configuring certificate authentication:
+    https://docs.microsoft.com/azure/active-directory/develop/active-directory-certificate-credentials#register-your-certificate-with-microsoft-identity-platform
+
     :param str tenant_id: ID of the service principal's tenant. Also called its 'directory' ID.
     :param str client_id: the service principal's client ID
     :param str certificate_path: path to a PEM-encoded certificate file including the private key. If not provided,

sdk/identity/azure-identity/azure/identity/_credentials/client_secret.py

@@ -12,7 +12,7 @@
 
 
 class ClientSecretCredential(ClientCredentialBase):
-    """Authenticates as a service principal using a client ID and client secret.
+    """Authenticates as a service principal using a client secret.
 
     :param str tenant_id: ID of the service principal's tenant. Also called its 'directory' ID.
     :param str client_id: the service principal's client ID

sdk/identity/azure-identity/azure/identity/_credentials/device_code.py

@@ -27,8 +27,9 @@ class DeviceCodeCredential(InteractiveCredential):
     A user must browse to the URL, enter the code, and authenticate with Azure Active Directory. If the user
     authenticates successfully, the credential receives an access token.
 
-    For more information about the device code flow, see Azure Active Directory documentation:
-    https://docs.microsoft.com/azure/active-directory/develop/v2-oauth2-device-code
+    This credential is primarily useful for authenticating a user in an environment without a web browser, such as an
+    SSH session. If a web browser is available, :class:`~azure.identity.InteractiveBrowserCredential` is more
+    convenient because it automatically opens a browser to the login page.
 
     :param str client_id: client ID of the application users will authenticate to. When not specified users will
           authenticate to an Azure development application.

sdk/identity/azure-identity/azure/identity/_credentials/managed_identity.py

@@ -28,6 +28,9 @@ class ManagedIdentityCredential(object):
     This credential defaults to using a system-assigned identity. To configure a user-assigned identity, use one of
     the keyword arguments.
 
+    See Azure Active Directory documentation for more information about configuring managed identity for applications:
+    https://docs.microsoft.com/azure/active-directory/managed-identities-azure-resources/overview
+
     :keyword str client_id: a user-assigned identity's client ID. This is supported in all hosting environments.
     :keyword identity_config: a mapping ``{parameter_name: value}`` specifying a user-assigned identity by its object
       or resource ID, for example ``{"object_id": "..."}``. Check the documentation for your hosting environment to

sdk/identity/azure-identity/azure/identity/aio/_credentials/certificate.py

@@ -22,6 +22,9 @@ class CertificateCredential(AsyncContextManager, GetTokenMixin):
 
     The certificate must have an RSA private key, because this credential signs assertions using RS256.
 
+    See Azure Active Directory documentation for more information on configuring certificate authentication:
+    https://docs.microsoft.com/azure/active-directory/develop/active-directory-certificate-credentials#register-your-certificate-with-microsoft-identity-platform
+
     :param str tenant_id: ID of the service principal's tenant. Also called its 'directory' ID.
     :param str client_id: the service principal's client ID
     :param str certificate_path: path to a PEM-encoded certificate file including the private key. If not provided,

sdk/identity/azure-identity/azure/identity/aio/_credentials/client_secret.py

@@ -17,7 +17,7 @@
 
 
 class ClientSecretCredential(AsyncContextManager, GetTokenMixin):
-    """Authenticates as a service principal using a client ID and client secret.
+    """Authenticates as a service principal using a client secret.
 
     :param str tenant_id: ID of the service principal's tenant. Also called its 'directory' ID.
     :param str client_id: the service principal's client ID

sdk/identity/azure-identity/azure/identity/aio/_credentials/managed_identity.py

@@ -26,6 +26,9 @@ class ManagedIdentityCredential(AsyncContextManager):
     This credential defaults to using a system-assigned identity. To configure a user-assigned identity, use one of
     the keyword arguments.
 
+    See Azure Active Directory documentation for more information about configuring managed identity for applications:
+    https://docs.microsoft.com/azure/active-directory/managed-identities-azure-resources/overview
+
     :keyword str client_id: a user-assigned identity's client ID. This is supported in all hosting environments.
     :keyword identity_config: a mapping ``{parameter_name: value}`` specifying a user-assigned identity by its object
       or resource ID, for example ``{"object_id": "..."}``. Check the documentation for your hosting environment to