revise Develop landing page banner for Studio 2.2

    <div class="cols dac-hero-content">

      <div class="col-1of2 col-push-1of2 dac-hero-figure">

        <img class="dac-hero-image" style="padding-top:32px"

          src="/images/develop/hero-layout-editor_2x.png">

          src="/images/develop/hero-layout-editor_2x.png"

          srcset="/images/develop/hero-layout-editor_2x.png 2x,

                  /images/develop/hero-layout-editor.png 1x">

      </div>

      <div class="col-1of2 col-pull-1of2" style="margin-bottom:40px">

        <h1 class="dac-hero-title">

            <a style="color:inherit" href="{@docRoot}studio/index.html">

            Android Studio 2.2 <nobr>is here!</nobr></a></h1>

            Android Studio 2.2!</a></h1>

<p class="dac-hero-description">The latest version of Android Studio includes a

rewritten layout editor with the new constraint layout, helping you build rich

UI with less work. </p>

<p class="dac-hero-description">There are 20+ new features in this release

focused on helping you code faster and smarter. With Android Studio 2.2 you

can:</p>

<p class="dac-hero-description">

There are 20+ new features in Android Studio 2.2, helping you code faster

and smarter.</p>

<ul class="dac-hero-description">

  <li>Develop your app user interface faster with the new Layout Editor &amp;

    Constraint Layout</li>

  <li>Develop smarter with the APK analyzer &amp; expanded code analysis</li>

  <li>Develop with the the latest Android 7.0 Nougat APIs &amp; features</li>

</ul>

<p style="margin-top:24px">

    <a class="dac-hero-cta" href="{@docRoot}studio/index.html">