Add DOI instructions to data link example

Author: twhiteaker

data_links.html

@@ -20,6 +20,7 @@ <h1>Zotero Search Demo with Data Links</h1>
       <p>This <a href="https://github.com/BLE-LTER/Zotero-JavaScript-Search-Client"
             rel="noopener">Zotero-JavaScript-Search-Client</a> example demonstrates how data links are added to a publication citation when DOIs are found within the <strong>Extra</strong> field in Zotero.
             The group is just a test group, and the data links aren't related to the publication in this example, but the example does illustrate the functionality. Look for the example to be replaced with a real-world example as users apply this functionality to their own libraries.</p>
+      <p>To include data links, add each DOI for data associated with a dataset to the <strong>Extra</strong> field in Zotero, with each DOI appearing on its own line.  The link must include https://doi.org/ in front of the DOI, as in https://doi.org/10.18739/A27D2Q702.</p>
       <form id="zoteroSearchForm" name="zoteroSearchForm">
          <input class="search-input" name="q" placeholder="Enter search term" type="text">
          <input type="submit" value="Search">