Correct install procedure for gunicorn.

Correct docs index links.

allianceauth/project_template/supervisor.conf

@@ -23,6 +23,7 @@ stopwaitsecs = 600
 killasgroup=true
 priority=998
 
+{% if gunicorn %}
 [program:gunicorn]
 user = allianceserver
 directory={{ project_directory }}
@@ -33,6 +34,7 @@ autostart=true
 autorestart=true
 stopsignal=INT
 
+{% endif %}
 [group:{{ project_name }}]
-programs=beat,worker,gunicorn
+programs=beat,worker{% if gunicorn %},gunicorn{% endif %}
 priority=999