sch2fig/sch2pdf: add copyright header, known bugs

sch2fig/sch2pdf

@@ -1,4 +1,23 @@
 #!/bin/bash
+#
+# sch2pdf - Generate PDF from schematics, using sch2fig
+#
+# Written 2016 by Werner Almesberger
+# Copyright 2016 by Werner Almesberger
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+
+#
+# Known bugs:
+# - expects first sheet to be index page
+# - only renders sub-sheets
+# - has all the limitations of sch2fig (see TODO)
+#
+
 
 usage()
 {