Add SHEETS walkthrough

pages/tutorials.html

@@ -23,6 +23,21 @@ <h2>GH Walkthrough</h2>
   </div>
 </div>
 
+<div class="row border my-4">
+  <div class="col-md-8 border p-3">
+    <h2>SHEETS Walkthrough</h2>
+    <p>This two-part walkthrough provides steps for using SHEETS' built-in development mode to prototype, test, and share a draft of your digital collection site. You also will learn how to create an example project using preexisting demo metadata, the <a href="https://github.com/CollectionBuilder/collectionbuilder-sheets" target="_blank">CollectionBuilder-SHEETS Template</a>, and GitHub Pages.</p>
+    <p class="alert alert-success">You will need to create a free GitHub account for this walkthrough, but no software installation is necessary.</p>
+
+  </div>
+  <div class="col-md-4 border p-3 pt-5">
+    <div class="text-center">
+      <a href="https://collectionbuilder.github.io/cb-docs/docs/walkthroughs/sheets-walkthrough/" class="btn btn-primary btn-lg" target="_blank" rel="noopener">Go to Walkthrough</a>
+      <br>
+    </div>
+  </div>
+</div>
+
 <div class="row border my-4">
   <div class="col-md-8 border p-3">
     <h2>CSV Walkthrough</h2>