Update news.html

Author: pgleeson

news.html

@@ -176,7 +176,7 @@ <h3>6) OpenWorm simulation stack updates</h3>
 
 <h3>7) Other announcements</h3>
 
-<p align="center"><kbd><a href="docs/OpenWormPoster_C_elegans_meeting_June_2021.pdf">
+<p align="center"><kbd><a href="https://github.com/openworm/Newsletter/raw/main/docs/OpenWormPoster_C_elegans_meeting_June_2021.pdf">
   <img src="https://raw.githubusercontent.com/openworm/Newsletter/main/img/OpenWormPoster2022.png" alt="OpenWormPoster2022" width="450"></a></kbd></p>
 
 <p class="lead">A poster presenting the latest status of the OpenWorm project was presented at the