Update runtime files
diff --git a/runtime/ftplugin/nroff.vim b/runtime/ftplugin/nroff.vim
new file mode 100644
index 0000000..069c02e
--- /dev/null
+++ b/runtime/ftplugin/nroff.vim
@@ -0,0 +1,11 @@
+" Vim filetype plugin
+" Language:	roff(7)
+" Maintainer:	Chris Spiegel <cspiegel@gmail.com>
+" Last Change:	2019 Apr 24
+
+if exists("b:did_ftplugin")
+  finish
+endif
+let b:did_ftplugin = 1
+
+setlocal commentstring=.\\\"%s