Separate OAuth 2.0 Login Servlet Docs

Issue gh-10367

Author: jzheaux

docs/modules/ROOT/nav.adoc

@@ -54,7 +54,9 @@
 *** xref:servlet/authorization/method-security.adoc[Method Security]
 *** xref:servlet/authorization/acls.adoc[Domain Object Security ACLs]
 ** xref:servlet/oauth2/index.adoc[OAuth2]
-*** xref:servlet/oauth2/oauth2-login.adoc[OAuth2 Log In]
+*** xref:servlet/oauth2/login/index.adoc[OAuth2 Log In]
+**** xref:servlet/oauth2/login/core.adoc[Core Configuration]
+**** xref:servlet/oauth2/login/advanced.adoc[Advanced Configuration]
 *** xref:servlet/oauth2/client/index.adoc[OAuth2 Client]
 **** xref:servlet/oauth2/client/core.adoc[Core Interfaces and Classes]
 **** xref:servlet/oauth2/client/authorization-grants.adoc[OAuth2 Authorization Grants]

docs/modules/ROOT/pages/servlet/appendix/namespace/http.adoc

@@ -863,7 +863,7 @@ Maps a `ForwardAuthenticationFailureHandler` to `authenticationFailureHandler` p
 
 [[nsa-oauth2-login]]
 == <oauth2-login>
-The xref:servlet/oauth2/oauth2-login.adoc#oauth2login[OAuth 2.0 Login] feature configures authentication support using an OAuth 2.0 and/or OpenID Connect 1.0 Provider.
+The xref:servlet/oauth2/login/index.adoc#oauth2login[OAuth 2.0 Login] feature configures authentication support using an OAuth 2.0 and/or OpenID Connect 1.0 Provider.
 
 
 [[nsa-oauth2-login-parents]]

docs/modules/ROOT/pages/servlet/authentication/index.adoc

@@ -14,7 +14,7 @@ These sections focus on specific ways you may want to authenticate and point bac
 // FIXME: brief description
 
 * xref:servlet/authentication/passwords/index.adoc#servlet-authentication-unpwd[Username and Password] - how to authenticate with a username/password
-* xref:servlet/oauth2/oauth2-login.adoc#oauth2login[OAuth 2.0 Login] - OAuth 2.0 Log In with OpenID Connect and non-standard OAuth 2.0 Login (i.e. GitHub)
+* xref:servlet/oauth2/login/index.adoc#oauth2login[OAuth 2.0 Login] - OAuth 2.0 Log In with OpenID Connect and non-standard OAuth 2.0 Login (i.e. GitHub)
 * xref:servlet/saml2/index.adoc#servlet-saml2[SAML 2.0 Login] - SAML 2.0 Log In
 * xref:servlet/authentication/rememberme.adoc#servlet-rememberme[Remember Me] - how to remember a user past session expiration
 * xref:servlet/authentication/jaas.adoc#servlet-jaas[JAAS Authentication] - authenticate with JAAS