new tutorial for how using  navigation in oro

new tutorial for how using  navigation in oro
add section or Override existing section
Update how_append_your_menu_links _to_existing _menu.rst
Update how_append_your_menu_links _to_existing _menu.rst
Delete how_append_your_menu_links _to_existing _menu.rst
first version tutorial how play with navigation in oro
Delete #how_append_your_link _to_existing _menu.rst#
resolve problem in words

modify 
Create create and fill navigation.yml
to
Create and fill navigation.yml
Change file name
Change file name
all change done
complete change
Delete inheritance-mapping.rst
ignore any update by me in this file
resize images
Delete add_item_page_result_click.png
remove space folder
revert file to 644
Merge branch 'master' of https://github.com/ibnab/documentation
Delete add_item_to_default_nav.png
Delete ov_item_in_default_nav.png