Add spreadsheets software setup instructions for LC workshops

Author: tobyhodges

_includes/lc/setup.html

@@ -1,3 +1,63 @@
+<div id=""spreadsheets-setup">
+  <h3>Spreadsheet Software</h3>
+  <p>
+    To interact with spreadsheets, we can use <a href="https://www.libreoffice.org">LibreOffice</a>, 
+    <a href="https://products.office.com/en-us/excel">Microsoft Excel</a>, 
+    <a href="https://www.gnumeric.org">Gnumeric</a>, 
+    <a href="https://www.openoffice.org">OpenOffice.org</a>, 
+    or other programs. 
+    Commands may differ a bit between programs, but general ideas for thinking about spreadsheets is the same.
+  </p>
+  <p>
+    For this lesson, if you don't have a spreadsheet program already, 
+    you can use [LibreOffice](https://www.libreoffice.org). 
+    It is a free, open source spreadsheet program.
+  </p>
+  <h4>Windows</h4>
+  <p>
+    <ul>
+      <li><strong>Download the Installer:</strong>
+        Install LibreOffice by going to the 
+        <a href="https://www.libreoffice.org/download/libreoffice-fresh/">installation page</a>.
+        The version for Windows should automatically be selected. 
+        Click <strong>Download</strong>. 
+        You will go to a page that asks about a donation, but you don't need to make one. 
+        Your download should begin automatically.</li>
+      <li><strong>Install LibreOffice:</strong>  
+        Once the installer is downloaded, double click on it and it should install.</li>
+    </ul>
+  </p>
+  <h4>Mac OS</h4>
+  <p>
+    <ul>
+      <li><strong>Download the Installer:</strong>
+        Install LibreOffice by going to the 
+        <a href="https://www.libreoffice.org/download/libreoffice-fresh/">installation page</a>.
+        The version for Mac OS should automatically be selected. 
+        Click <strong>Download</strong>. 
+        You will go to a page that asks about a donation, but you don't need to make one. 
+        Your download should begin automatically.</li>
+      <li><strong>Install LibreOffice:</strong>  
+        The file <code>LibreOffice\_X.X.X\_MacOS\_x86-64</code> (whichever version of LibreOffice you have selected) should have been downloaded. 
+        Double click on this file, and LibreOffice will be installed.</li>
+    </ul>
+  </p>
+  <h4>Linux</h4>
+  <p>
+    <ul>
+      <li><strong>Download the Installer:</strong>
+        Install LibreOffice by going to the 
+        <a href="https://www.libreoffice.org/download/libreoffice-fresh/">installation page</a>.
+        The version for Linux should automatically be selected. 
+        Click <strong>Download</strong>. 
+        You will go to a page that asks about a donation, but you don't need to make one. 
+        Your download should begin automatically.</li>
+      <li><strong>Install LibreOffice:</strong>  
+        Once the installer is downloaded, double click on it and it should install.</li>
+    </ul>
+  </p>
+</div>
+
 <div id="shell-setup"> {% comment %} Start of 'shell' section. {% endcomment %}
   <h3>The Bash Shell</h3>
   <p>