#2539 add man page entry for 'headerbar'

git-svn-id: https://xpra.org/svn/Xpra/trunk@26997 3bb7dfac-3a0b-4e04-842a-767bc560f471

src/man/xpra.1

@@ -1203,6 +1203,12 @@ forwarded through the same xpra server: modal windows will be made modal
 for all the applications forwarded by xpra rather than just the one
 application which owns that window.
 .TP
+\fB--headerbar\fP=\fIyes\fP|\fIno\fP|\fIforce\fP
+Replaces the window's standard title bar with a custom one which
+is used to give access to xpra specific window controls.
+This feature can have side effects and it is incompatible with OpenGL
+acceleration on MS Windows.
+.TP
 \fB--password-file\fP=\fIFILENAME\fP
 Supply the password to be used for connecting to a server that
 uses authentication. See \fIauth\fP, \fItcp-auth\fP, \fIssl-auth\fP