fix #71 and #73: add support for outdir template and enhance docs

kleingebaeck.pod

@@ -55,7 +55,7 @@ Be careful  if you want  to change the  template.  The variable  is a
 multiline string surrounded  by three double quotes. You  can left out
 certain   fields  and   use  any   formatting  you   like.  Refer   to
 L<https://pkg.go.dev/text/template>  for   details  how  to   write  a
-template.
+template. Also read the TEMPLATES section below.
 
 If you're on  windows and want to customize the  output directory, put
 it into single  quotes to avoid the backslashes  interpreted as escape
@@ -63,6 +63,91 @@ chars like this:
 
     outdir = 'C:\Data\Ads'
 
+=head1 TEMPLATES
+
+Various parts  of the configuration  can be modified  using templates:
+the output directory, the ad directory and the ad listing itself.
+
+=head2 OUTPUT DIR TEMPLATE
+
+The config varialbe C<outdir> or the command line parameter C<-o> take a
+template which may contain:
+
+=over
+
+=item C<{{.Year}}>
+
+=item C<{{.Month}}>
+
+=item C<{{.Day}}>
+
+=back
+
+That way you can create a new output directory for every backup
+run. For example:
+
+    outdir = "/home/backups/ads-{{.Year}}-{{.Month}}-{{.Day}}"
+
+Or using the command line flag:
+
+    -o "/home/backups/ads-{{.Year}}-{{.Month}}-{{.Day}}"
+
+The default value is C<.> - the current directory.
+
+=head2 AD DIRECTORY TEMPLATE
+
+The ad directory name can be modified using the following ad values:
+
+=over
+
+=item {{.Price}}
+
+=item {{.ID}}
+
+=item {{.Category}}
+
+=item {{.Condition}}
+
+=item {{.Created}}
+
+=item {{.Slug}}
+
+=item {{.Text}}
+
+=back
+
+It can only be configured in the config file. By default only
+C<{{.Slug}}> is being used, this is the title of the ad in url format.
+
+=head2 AD TEMPLATE
+
+The ad listing itself can be modified as well, using the same
+variables as the ad name template above.
+
+This is the default template:
+
+    Title: {{.Title}}
+    Price: {{.Price}}
+    Id: {{.ID}}
+    Category: {{.Category}}
+    Condition: {{.Condition}}
+    Created: {{.Created}}
+    Expire: {{.Expire}}
+    
+    {{.Text}}
+
+The config parameter to modify is C<template>. See example.conf in the
+source repository. Please take care, since this is a multiline
+string. This is how it shall look if you modify it:
+
+    template="""
+    Title: {{.Title}}
+    
+    {{.Text}}
+    """
+
+That is, the content between the two C<"""> chars is the template.
+
 =head1 SETUP
 
 To setup the tool, you need to lookup your userid on