adding User ID submodules to download page (prebid#1400)

Author: bretg

download.md

@@ -416,6 +416,21 @@ Note: If you receive an error during download you most likely selected a configu
 </div>
 </div>
  {% endfor %}
+<div class="col-md-4"><div class="checkbox">
+<label><input type="checkbox" moduleCode="pubCommonIdSystem" class="bidder-check-box"> User ID: PubCommon ID</label>
+</div></div>
+<div class="col-md-4"><div class="checkbox">
+<label><input type="checkbox" moduleCode="unifiedIdSystem" class="bidder-check-box"> User ID: Unified ID</label>
+</div></div>
+<div class="col-md-4"><div class="checkbox">
+<label><input type="checkbox" moduleCode="digiTrustIdSystem" class="bidder-check-box"> User ID: DigiTrust ID</label>
+</div></div>
+<div class="col-md-4"><div class="checkbox">
+<label><input type="checkbox" moduleCode="id5IdSystem" class="bidder-check-box"> User ID: ID5 ID</label>
+</div></div>
+<div class="col-md-4"><div class="checkbox">
+<label><input type="checkbox" moduleCode="criteortusIdSystem" class="bidder-check-box"> User ID: Criteo RTUS ID</label>
+</div></div>
 </div>
 
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