commiting v12 changess (#8478)

README.md

@@ -22,6 +22,7 @@ deep learning systems, and interesting insights of DL systems for hackers.
 
 What's New
 ----------
+* [Version 0.12.0 Release](https://github.com/apache/incubator-mxnet/releases/tag/0.12.0) - MXNet 0.12.0 Release.
 * [Version 0.11.0 Release](https://github.com/apache/incubator-mxnet/releases/tag/0.11.0) - MXNet 0.11.0 Release.
 * [Apache Incubator](http://incubator.apache.org/projects/mxnet.html) - We are now an Apache Incubator project.
 * [Version 0.10.0 Release](https://github.com/dmlc/mxnet/releases/tag/v0.10.0) - MXNet 0.10.0 Release.

docs/_static/mxnet-theme/index.html

@@ -32,8 +32,8 @@ <h3>Introducing - Gluon</h3>
         <a href="http://gluon.mxnet.io">Learn More</a>
       </div>
       <div class="col-lg-4 col-sm-12">
-        <h3>MXNet 0.11.0 Released</h3>
-        <p>We're excited to announce the release of MXNet 0.11.0! Check out the release notes for latest updates.</p>
+        <h3>MXNet 0.12.0 Released</h3>
+        <p>We're excited to announce the release of MXNet 0.12.0! Check out the release notes for latest updates.</p>
         <a href="https://github.com/dmlc/mxnet/releases">Learn More</a>
       </div>
       <div class="col-lg-4 col-sm-12">