Add documentation

index.html

@@ -65,7 +65,7 @@ <h2>Getting started<a class="headerlink" href="#getting-started" title="Permalin
               <ol class="arabic simple">
                 <li>Go to the <a class="reference external" href="https://github.com/DARIAH-DE/TopicsExplorer/releases">release-section</a> and download the <strong>source code</strong> as ZIP archive.</li>
                 <li>Unzip the archive, e.g. using <code>unzip</code> via the command-line.</li>
-                <li>Make sure you have Python 3.6 and <a class="reference external" href="https://docs.pipenv.org/">Pipenv</a> installed.</li>
+                <li>Make sure you have <a class="reference external" href="https://docs.pipenv.org/">Pipenv</a> installed (if not: use <code>pip install pipenv</code>).</li>
                 <li>Run <code>pipenv install</code>, and afterwards <code>pipenv shell</code>.</li>
                 <li>To start the application, type <code>python topicsexplorer.py</code>, and press enter.</li>
               </ol>