DOCSP-25803 add configuration linking (#106)

* DOCSP-25803 add configuration linking

* Review feedback

Author: Dave Cuthbert

source/reference/configuration.txt

@@ -12,16 +12,17 @@ Configuration
    :depth: 2
    :class: singlecol
 
-You can configure :program:`mongosync` instances at startup using a configuration
-file.  The configuration file contains settings that are the equivalent of
-``mongosync`` command-line options.
-
+You can configure :program:`mongosync` instances at startup using a
+configuration file.  The configuration file contains settings that are
+the equivalent of ``mongosync`` command-line options.
 
 Configuration File
 ==================
 
-Most :program:`mongosync` command-line options can be written to a YAML file.
-The configuration file specifies values for each setting using YAML format.
+Most :program:`mongosync` command-line options can be written to a YAML
+file. The configuration file specifies values for each setting using
+YAML format. 
+
 For example:
 
 .. code-block:: yaml
@@ -31,8 +32,8 @@ For example:
    logPath: "/var/log/mongosync"
    verbosity: "WARN"
 
-To use a configuration file, start ``mongosync`` with the :option:`--config`
-option to set the path to the file:
+To use a configuration file, start ``mongosync`` with the
+:option:`--config` option to set the path to the file:
 
 .. code-block:: console
 
@@ -41,6 +42,12 @@ option to set the path to the file:
 Options
 =======
 
+.. note::
+
+   The ``start`` command provides additional options for features like
+   ``reversibility`` and ``user write blocking``. For more details, see
+   the :ref:`start <c2c-api-start>` API documentation.
+
 .. |opt-term| replace:: setting
 
 .. setting:: cluster0