[shotwell] doc: Add --fullscreen option to manpage

[Jens Georg <jensgeorg src gnome org>]

commit 0f8afb46d62765181bb2a2c6ab16ec8a55761dce
Author: Jens Georg <mail jensge org>
Date:   Mon May 29 22:55:13 2017 +0200

    doc: Add --fullscreen option to manpage

 help/shotwell.1 |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/help/shotwell.1 b/help/shotwell.1
index 195143f..a68f387 100644
--- a/help/shotwell.1
+++ b/help/shotwell.1
@@ -26,6 +26,11 @@ Path to Shotwell's private data
 Do not monitor library directory at runtime for changes
 .RE
 
+.B \-f, \-\-fullscreen
+.RS
+Open the viewer mode in fullscreen. Has no effect in library mode.
+.RE
+
 .B \-\-no-startup-progress
 .RS
 Don't display startup progress meter