Fix `'myst' cross-reference target not found` warnings

Also:
- Use auto-generated table of contents in tool schema

doc/source/admin/authentication.md

@@ -3,9 +3,9 @@
 Galaxy supports the following authentication mechanisms:
 
 * [Galaxy Database](#galaxy-database) - Galaxy-specific login using e-mail address and password (the default);
-* [OIDC and OAuth2.0](#OIDC-and-OAuth2.0) - Login to Galaxy using your Google account, without having to create a Galaxy user;
+* [OIDC and OAuth2.0](#oidc-and-oauth2-0) - Login to Galaxy using your Google account, without having to create a Galaxy user;
 * [Authentication Framework](#authentication-framework) - A plugin-driven framework supporting LDAP/Active Directory and PAM;
-* [Proxy Authentication](#proxy_authentication) - HTTP [remote user](http://httpd.apache.org/docs/current/mod/mod_cgi.html#env) provided by any front-end Web server.
+* [Proxy Authentication](#remote-user-authentication) - HTTP [remote user](http://httpd.apache.org/docs/current/mod/mod_cgi.html#env) provided by any front-end Web server.
 
 ## Galaxy Database
 

doc/source/conf.py

@@ -53,6 +53,8 @@ myst_enable_extensions = [
     "deflist",
     "substitution",
 ]
+myst_heading_anchors = 5
+myst_heading_slug_func = "docutils.nodes.make_id"
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ["_templates"]