Doc: Move generalized_filters to admin

This is not a man page, so move it to the admin dir
instead of "man".

Change-Id: I6d128a5bc30b8d9ac1a0b7a200088b39a1777b05

doc/source/admin/index.rst

@@ -27,6 +27,7 @@ Amazon EC2 Elastic Block Storage (EBS) offering.
    blockstorage-api-throughput.rst
    blockstorage-manage-volumes.rst
    blockstorage-troubleshoot.rst
+   generalized_filters.rst
 
 .. _`Storage Decisions`: https://docs.openstack.org/ops-guide/arch-storage.html
 .. _`OpenStack Operations Guide`: https://docs.openstack.org/ops-guide/

doc/source/index.rst

@@ -99,7 +99,6 @@ Additional 'man page' style documentation for Cinder may be seen below.
    :maxdepth: 2
 
    man/cinder-manage
-   man/generalized_filters
 
 Drivers
 ~~~~~~~