[console] application: Add a placeholder for each option that takes an argument

[Zander Brown <zbrown src gnome org>]

commit 92b9638b7d17047cd6e5da009449c402f7724eb2
Author: Simon McVittie <smcv debian org>
Date:   Sat Apr 9 17:34:16 2022 +0100

    application: Add a placeholder for each option that takes an argument
    
    This makes the --help output a bit clearer.
    
    Signed-off-by: Simon McVittie <smcv debian org>

 src/kgx-application.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/src/kgx-application.c b/src/kgx-application.c
index ee5fb77..6e8e415 100644
--- a/src/kgx-application.c
+++ b/src/kgx-application.c
@@ -699,7 +699,7 @@ static GOptionEntry entries[] = {
     G_OPTION_ARG_FILENAME,
     NULL,
     N_("Execute the argument to this option inside the terminal"),
-    NULL
+    N_("COMMAND")
   },
   {
     "working-directory",
@@ -727,7 +727,7 @@ static GOptionEntry entries[] = {
     G_OPTION_ARG_STRING,
     NULL,
     N_("Set the initial window title"),
-    NULL
+    N_("TITLE")
   },
   {
     "set-shell",
@@ -736,7 +736,7 @@ static GOptionEntry entries[] = {
     G_OPTION_ARG_STRING_ARRAY,
     NULL,
     N_("ADVANCED: Set the shell to launch"),
-    NULL
+    N_("SHELL")
   },
   {
     "set-scrollback",
@@ -745,7 +745,7 @@ static GOptionEntry entries[] = {
     G_OPTION_ARG_INT64,
     NULL,
     N_("ADVANCED: Set the scrollback length"),
-    NULL
+    N_("LINES")
   },
   { NULL }
 };