i3-nagbar.man: updated man page to include all options

several options were not documented in the man page.

man/i3-nagbar.man

@@ -9,7 +9,29 @@ i3-nagbar - displays an error bar on top of your screen
 
 == SYNOPSIS
 
-i3-nagbar -m 'message' -b 'label' 'action'
+i3-nagbar [-m <message>] [-b <button> <action>] [-t warning|error] [-f <font>] [-v]
+
+== OPTIONS
+
+*-v, --version*::
+Display version number and exit.
+
+*-h, --help*::
+Display a short help-message and exit.
+
+*-t, --type* 'type'::
+Display either a warning or error message. This only changes the color scheme
+for the i3-nagbar. Default: error.
+
+*-m, --message* 'message'::
+Display 'message' as text on the left of the i3-nagbar.
+
+*-f, --font* 'font'::
+Select font that is being used.
+
+*-b, --button* 'button' 'action'::
+Create a button with text 'button'. The 'action' are the shell commands that
+will be executed by this button. Multiple buttons can be defined.
 
 == DESCRIPTION