Improve documantion of many plugins

Specifically the configuration examples are now indented properly.

plugins/syncthing/syncthing_

@@ -2,36 +2,56 @@
 # -*- sh -*-
 : <<=cut
 =head1 NAME
+
 syncthing_ - Plugin to monitor Syncthing server
 
+
 =head1 DESCRIPTION
+
 This plugin gathers metrics from a Syncthing server.
 
 This plugin requires the jq utility : https://stedolan.github.io/jq/
 This plugin requires the cURL utility : https://curl.haxx.se/
 
-Available plugins :
-syncthing_cpu       #
-syncthing_mem       #
-syncthing_goroutine #
-syncthing_transfer  #
-syncthing_uptime    #
+Available wildcard plugin features:
+
+=over 4
+
+=item syncthing_cpu
+
+=item syncthing_mem
+
+=item syncthing_goroutine
+
+=item syncthing_transfer
+
+=item syncthing_uptime
+
+=back
+
 
 =head1 CONFIGURATION
 To make the plugin connect to the Syncthing server one has to use this type of
-configuration
-[syncthing_*]
+configuration:
+
+ [syncthing_*]
+ env.syncthing_apikey myapikey0123456789
+ env.syncthing_host 127.0.0.1
+ env.syncthing_port 8384
+ env.syncthing_proto http
 
-env.syncthing_apikey myapikey0123456789
-env.syncthing_host 127.0.0.1
-env.syncthing_port 8384
-env.syncthing_proto http
 
 =head1 AUTHOR
+
 Pierre-Alain TORET <pierre-alain.toret@protonmail.com>
 
+
 =head1 LICENSE
+
 MIT
+
+SPDX-License-Identifier: MIT
+
 =cut
 
 syncthing_apikey=${syncthing_apikey:-}