display error message if no POD found

Author: szabgab

bin/p6doc

@@ -46,6 +46,10 @@ sub locate-module(Str $modulename) {
 
 sub show-docs(Str $path, :$section) {
    my $pager = %*ENV<PAGER> // ($*OS eq 'MSWin32' ?? 'more' !! 'less');
+   if not open($path).lines.grep( /^\=/ )  {
+      say "No POD found in $path";
+      return;
+   }
    if $section.defined {
        %*ENV<PERL6_POD_HEADING> = $section;
       my $i = findbin() ~ '../lib';