[emacs] Add snippets for latex mode.

.emacs.d/snippets/latex-mode/array.yasnippet

@@ -0,0 +1,9 @@
+# -*- mode: snippet -*-
+# contributor : Peter Urbak <peter@dragonwasrobot.com>
+# key : arr
+# group: environments
+# name : \begin{array} ... \end{array}
+# --
+\begin{array}{$1}
+  $0
+\end{array}