elsarticle.lyx: add info how to get line numbers (info taken from the official elsarticle template file)

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/branches/BRANCH_2_0_X@40576 a592a061-630c-0410-9148-cb99ea01b6c8

lib/templates/elsarticle.lyx

@@ -6,6 +6,9 @@
 \begin_preamble
 % specify here the journal
 \journal{Example: Nuclear Physics B}
+
+% use this if you need line numbers
+%\usepackage{lineno}
 \end_preamble
 \use_default_options false
 \begin_modules
@@ -701,6 +704,36 @@ MSC
 \end_inset
 
 
+\end_layout
+
+\begin_layout Standard
+\begin_inset Note Note
+status open
+
+\begin_layout Plain Layout
+Use here the command 
+\begin_inset ERT
+status collapsed
+
+\begin_layout Plain Layout
+
+
+\backslash
+linenumbers 
+\end_layout
+
+\end_inset
+
+ and enable the package 
+\series bold
+lineno
+\series default
+ in the preamble if you need line numbers.
+\end_layout
+
+\end_inset
+
+
 \end_layout
 
 \begin_layout Section