Update splash screen

Add some setup steps - configure git and install command line tools.
![screen shot 2014-11-23 at 5 54 06 pm](https://cloud.githubusercontent.com/assets/574393/5158081/cce337f8-7339-11e4-83ac-4f709d47d163.png)

Actually if we're being nitpicky in macs it's .bash_profile

On Mon, Nov 24, 2014 at 9:56 AM, Yonatan Bergman <notifications@github.com>
wrote:

> In app/views/splash/index.html.erb:
>
> > @@ -18,6 +18,15 @@
> >        <textarea class="code" spellcheck="false" onclick="this.focus();this.select();">curl -s <%= view.script_url %> &gt; /tmp/install-boxen; bash /tmp/install-boxen</textarea>
> >        <h2>Run this command in your terminal to install Boxen on your machine.</h2>
> >        <h3>Go ahead. <a href="<%= view.script_path %>">Take a peek</a>.</h3>
> > +      <h2>Before starting, make sure to:</h2>
> > +      <ul>
> > +        <li>Set up GitHub SSH access on your machine, with permissions for the <a href="https://www.github.com/TheGiftsProject">TheGiftsProject</a> repository</li>
> > +        <li>Install OS X Command Line Tools: <textarea class="code" spellcheck="false" onclick="this.focus();this.select();">xcode-select --install</textarea></li>
> > +      </ul>
> > +      <h2>After you're done, don't forget to:</h2>
> > +      <ul>
> > +        <li>Add to your .zshrc: <textarea class="code" spellcheck="false" onclick="this.focus();this.select();">source /opt/boxen/env.sh</textarea></li>
>
> or .bashrc :)
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/TheGiftsProject/boxen-web/pull/1/files#r20776026>.
>