cleaned up single node external loadbalancer install topic

layouts/shortcodes/note_server-tags.html

@@ -0,0 +1,7 @@
+<blockquote>
+	<p><strong>Note:</strong></p>
+	<ul>
+		<li><code>rancher/rancher</code> is hosted on <a href="https://hub.docker.com/r/rancher/rancher/tags/">DockerHub</a>. If you don't have access to DockerHub, or you are installing Rancher without an internet connection, refer to <a href="/rancher/v2.x/en/installation/air-gap-installation/install-from-private-registry/">Installing From a Private Registry</a>.</li>
+		<li>For a list of other Rancher Server tags available, refer to <a href="/rancher/v2.x/en/installation/server-tags/">Rancher Server Tags</a>.</li>
+	</ul>
+</blockquote>

layouts/shortcodes/requirements_os.html

@@ -5,5 +5,4 @@
 		<li>Red Hat Enterprise Linux 7.5 (64-bit)</li>
 		<li>RancherOS 1.3.0 (64-bit)</li>
 	</ul>
-        <p>If you are using RancherOS, make sure you switch the Docker engine to a supported version using <code>sudo ros engine switch docker-17.03.2-ce</code></p>
 </div>

layouts/shortcodes/requirements_software.html

@@ -9,6 +9,7 @@
 				<li><code>1.13.1</code></li>
 				<li><code>17.03.02</code></li>
 			</ul>
+			<br/>
 			<p><a href="https://docs.docker.com/install/">Docker Documentation: Installation Instructions</a></p>
 		</li>
 	</ul>