Open external links in new tab/window

public/index.html

@@ -190,7 +190,7 @@ <h3 class="card-title">About The Data</h3>
                         The coronavirus page on Gov.gg was last updated <strong id="lastUpdated"></strong>. The data on this page is cached for 30 minutes and will next refresh <strong id="nextRefresh"></strong>.
                       </div>
                       <div class="col-12 col-md-12 col-lg-4 order-1 order-md-2">
-                        <a href="https://gov.gg/selfisolate" class="btn btn-lg btn-danger btn-block">Should I self-isolate?</a>            
+                        <a href="https://gov.gg/selfisolate" class="btn btn-lg btn-danger btn-block" target="_blank">Should I self-isolate?</a>
                       </div>
                     </div>
                   </div>
@@ -247,10 +247,10 @@ <h5 class="card-title m-0">Tracking Graphs</h5>
       <footer class="main-footer">
         <!-- To the right -->
         <div class="float-right d-none d-sm-inline">
-          Original data source: <a href="https://gov.gg/coronavirus">Gov.gg</a>
+          Original data source: <a href="https://gov.gg/coronavirus" target="_blank">Gov.gg</a>
         </div>
         <!-- Default to the left -->
-        <strong>Copyright &copy; 2020 <a href="https://kodo.gg">Kodo.gg</a>.</strong> All rights reserved.
+        <strong>Copyright &copy; 2020 <a href="https://kodo.gg" target="_blank">Kodo.gg</a>.</strong> All rights reserved.
       </footer>
     </div>
     <!-- ./wrapper -->
@@ -266,7 +266,7 @@ <h4 class="modal-title">About This Site</h4>
           </div>
           <div class="modal-body">
             <p>This site has been created and is maintained by Adrian Ritchie.  For enquiries about the site, please email: <a href="mailto:ar@kodo.gg?subject=Guernsey%20Covid-19%20Tracker">ar@kodo.gg</a>.</p>
-            <p>The source code for the site is available on <a href="https://github.com/adrianritchie/GG_Covid_19">GitHub <i class="fab fa-github"></i></a>.  If you are able to, please submit a pull-request for any enhancements to make this site better.</p>
+            <p>The source code for the site is available on <a href="https://github.com/adrianritchie/GG_Covid_19" target="_blank">GitHub <i class="fab fa-github"></i></a>.  If you are able to, please submit a pull-request for any enhancements to make this site better.</p>
           </div>
           <div class="modal-footer justify-content-between">
             <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>