restore latest Git installer instructions

_includes/install_instructions/git.html

@@ -40,17 +40,21 @@ <h3>Git</h3>
       </article>
       <article role="tabpanel" class="tab-pane" id="git-macos">
         <p>
-          <strong>For macOS</strong>, install Git for Mac
-          by downloading and running the most recent "mavericks" installer from
-          <a href="http://sourceforge.net/projects/git-osx-installer/files/">this list</a>.
-          Because this installer is not signed by the developer, you may have to
-          right click (control click) on the .pkg file, click Open, and click
-          Open on the pop up window.
-          After installing Git, there will not be anything in your <code>/Applications</code> folder,
-          as Git is a command line program.
+          Please open the Terminal app, type <code>git --version</code> and press 
+          <kbd>Enter</kbd>/<kbd>Return</kbd>. If it's not installed already, 
+          follow the instructions to <code>Install</code> the "command line 
+          developer tools". <strong>Do not click</strong> "Get Xcode", because that will 
+          take too long and is not necessary for our Git lesson.
+          After installing these tools, there won't be anything in your <code>/Applications</code>
+          folder, as they and Git are command line programs.
           <strong>For older versions of OS X (10.5-10.8)</strong> use the
           most recent available installer labelled "snow-leopard"
           <a href="http://sourceforge.net/projects/git-osx-installer/files/">available here</a>.
+          (Note: this project is no longer maintained.)
+          Because this installer is not signed by the developer, you may have to
+          right click (control click) on the .pkg file, click Open, and click
+          Open in the pop-up dialog. You can watch 
+          <a href="https://www.youtube.com/watch?v=9LQhwETCdwY ">a video tutorial about this case</a>.
         </p>
         <h4>Video Tutorial</h4>
         <div class="yt-wrapper2">