[gnome-screenshot] filename-builder: improve translators comments

[Cosimo Cecchi <cosimoc src gnome org>]

commit 96631ab741617b7b9394bbff970c27688c7a39b4
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Sun May 21 16:56:25 2017 -0700

    filename-builder: improve translators comments
    
    https://bugzilla.gnome.org/show_bug.cgi?id=782818

 src/screenshot-filename-builder.c |   16 +++++++++++-----
 1 files changed, 11 insertions(+), 5 deletions(-)
---
diff --git a/src/screenshot-filename-builder.c b/src/screenshot-filename-builder.c
index 7ad4371..48f9536 100644
--- a/src/screenshot-filename-builder.c
+++ b/src/screenshot-filename-builder.c
@@ -138,15 +138,21 @@ build_path (AsyncExistenceJob *job)
 
   if (job->iteration == 0)
     {
-      /* translators: this is the name of the file that gets made up
-       * with the screenshot if the entire screen is taken */
+      /* translators: this is the name of the file that gets made up with the
+       * screenshot if the entire screen is taken. The first placeholder is a
+       * timestamp (e.g. "2017-05-21 12-24-03"); the second placeholder is the
+       * file format (e.g. "png").
+       */
       file_name = g_strdup_printf (_("Screenshot from %s.%s"), origin, file_type);
     }
   else
     {
-      /* translators: this is the name of the file that gets
-       * made up with the screenshot if the entire screen is
-       * taken */
+      /* translators: this is the name of the file that gets made up with the
+       * screenshot if the entire screen is taken and the simpler filename
+       * already exists. The first and second placeholders are a timestamp and
+       * a counter to make it unique (e.g. "2017-05-21 12-24-03 - 2"); the third
+       * placeholder is the file format (e.g. "png").
+       */
       file_name = g_strdup_printf (_("Screenshot from %s - %d.%s"), origin, job->iteration, file_type);
     }