Cleanup cc-by-sa and fix boards navigation

_templates/cc-by-sa.html

-<a href="https://creativecommons.org/licenses/by-sa/4.0/">
+<a href="https://creativecommons.org/licenses/by-sa/4.0/" style="text-decoration:none">
     <img src="https://mirrors.creativecommons.org/presskit/buttons/88x31/svg/by-sa.svg"/>
+    <p>This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.</p>
 </a>

boards/index.rst

@@ -36,8 +36,7 @@ started.
     modifications done to the hardware or software solutions provided by beagleboard.org foundation.
 
 .. toctree::
-   :maxdepth: 2
-   :hidden:
+   :maxdepth: 1
 
    /boards/beagleplay/index
    /boards/beaglebone/ai-64/index

index.rst

@@ -397,12 +397,3 @@ Indices and tables
 
 * :ref:`glossary`
 * :ref:`genindex`
-
-This work is licensed under a `Creative Commons Attribution-ShareAlike 4.0 International License <http://creativecommons.org/licenses/by-sa/4.0/>`_. 
-
-Attribute original work to BeagleBoard.org Foundation.
-
-.. image:: https://licensebuttons.net/l/by-sa/4.0/88x31.png
-    :width: 88px
-    :height: 31px
-    :target: http://creativecommons.org/licenses/by-sa/4.0/