Update according DOCS

Each path use a index.rst file to include all the rst files:
1). Add missing index.rst
2). Rename some file to index.rst
3). Ude a index.rst to include all the community labs(currently all
    the labs are at the top level)

Change-Id: I9bb6903328a8d445121982dd662df9eeceb23ff5
Signed-off-by: Julien <zhang.jun3g@zte.com.cn>