fix package provide statement shellfilter module

src/modules/shellfilter-0.1.8.tm

@@ -8,7 +8,7 @@
 # - as presumably the reads/writes from a bidirectional channel could be diverted off to unidirectional pipelines for processing with less work
 # (and maybe even better speed/efficiency if the data volume is asymmetrical and there is significant processing on one direction)
 #
-package require shellfilter [namespace eval shellfilter {
+package provide shellfilter [namespace eval shellfilter {
     variable version
     set version 0.1.8
 }]