reorganize the content structure:
- Add the new "Network Interfaces Overview" section
- Reorganize the document structure and optimize formatting
Signed-off-by: nuttxs <zhaoqing.zhang@sony.com>
by index or address
- dns_del_nameserver()
- dns_del_nameserver_by_index()
Update the "DNS function" section in 11_network.rst, and create
the netlib API documentation in netlib/index.rst
Signed-off-by: nuttxs <zhaoqing.zhang@sony.com>