plugins: clean up plugin descriptions

- Make plugin descriptions more consistent
  so the output of "show plugin" can be
  used in the wiki.

Change-Id: I4c6feb11e7dcc5a4cf0848eed37f1d3b035c7dda
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>

src/plugins/nsh/nsh.c

@@ -273,7 +273,7 @@ VLIB_INIT_FUNCTION (nsh_init);
 /* *INDENT-OFF* */
 VLIB_PLUGIN_REGISTER () = {
     .version = VPP_BUILD_VER,
-    .description = "Network Service Header",
+    .description = "Network Service Header (NSH)",
 };
 /* *INDENT-ON* */