refactor extensions -> services

Signed-off-by: Christian Richter <crichter@owncloud.com>

docs/services/idm/_index.md

@@ -0,0 +1,30 @@
+---
+title: IDM
+date: 2022-03-02T00:00:00+00:00
+weight: 20
+geekdocRepo: https://github.com/owncloud/ocis
+geekdocEditPath: edit/master/docs/extensions/idm
+geekdocFilePath: _index.md
+geekdocCollapseSection: true
+---
+
+## Abstract
+
+The IDM service provides a minimal LDAP Service (based on https://github.com/libregraph/idm) for oCIS. It is started as part of
+the default configuration and serves as a central place for storing user and group information.
+
+It is mainly targeted at small oCIS installations. For larger setups it is recommended to replace IDM with a "real" LDAP server
+or to switch to an external Identity Management Solution.
+
+IDM listens on port 9325 by default. In the default configuration it only accepts TLS protected connections (LDAPS). The BaseDN
+of the LDAP tree is `o=libregraph-idm`. IDM gives LDAP write permissions to a single user 
+(DN: `uid=libregraph,ou=sysusers,o=libregraph-idm`). Any other authenticated user has read-only access. IDM stores its data in a
+[boltdb](https://github.com/etcd-io/bbolt) file `idm/ocis.boltdb` inside the oCIS base data directory.
+
+Note: IDM is limited in its functionality. It only supports a subset of the LDAP operations (namely BIND, SEARCH, ADD, MODIFY, DELETE).
+Also IDM currently does not do any schema verification (e.g. structural vs. auxiliary object classes, require and option attributes,
+syntax checks, ...). So it's not meant as a general purpose LDAP server.
+
+## Table of Contents
+
+{{< toc-tree >}}