Add example YAML file link for group analysis

Author: jpellman

docs/user/_sources/group_analysis.txt

@@ -26,7 +26,7 @@ As with subject list and pipeline configuration, there are two ways to set up FS
 Using a Text Editor
 ^^^^^^^^^^^^^^^^^^^^
 
-Similar to the pipeline and data configuration YAMLs for the pipeline and subject list specification steps, you can generate a group analysis configuration as a YAML.  A list of possible keys and values for this YAML are listed below.
+Similar to the pipeline and data configuration YAMLs for the pipeline and subject list specification steps, you can generate a group analysis configuration as a YAML.  An example of such a file can be found `here <https://raw.githubusercontent.com/FCP-INDI/C-PAC/master/configs/config_fsl.yml>`_.  A list of possible keys and values for this YAML are listed below.
 
     +-------------------------------+------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------+
     | Key                           | Description                                                                                                                  | Potential Values                                                                   |