add start and end date for bod members

Signed-off-by: Toshaan Bharvani <toshaan@vantosh.com>

themes/openpowerfoundation/layouts/boardofdirectors/list.html

@@ -5,6 +5,9 @@
 	<div class="row">
 		<h1 class="section-header my-3 my-md-5 pb-2 pb-md-3 text-center">{{ .Title }}</h1>
 		{{ range .Data.Pages.ByWeight }}
+			{{ $start := time (.Param "start") }}
+			{{ $end := time (.Param "end") }}
+			{{ if and (le now $end) (ge now $start) }}
 				{{ $personfilename := .File.BaseFileName }}
 				{{ $personfile := printf "%s/%s" "persons" $personfilename }}
 				<article class="post__article col-10 offset-1 row mb-4 pt-4">
@@ -33,6 +36,7 @@
 					</div>
 				</article>
 			{{ end }}
+		{{ end }}
 	</div>
 </div>
 </main>