pike customise and configure dashboard guide is wrong

[Frank]

This bug tracker is for errors with the documentation, use the following as a template and remove or add fields as you see fit. Convert [ ] into [x] to check boxes:

- [x] This doc is inaccurate in this way: The guide is completely wrong and simply breaks the dashboard when followed.
More accurately, the folder paths in the htlm file use css instead of scss as the parent directory. The file name for the custom css needs to be .scss not .css.
The guide seems to be calling for PNG but it looks like the standard is SVG now and PNG is not accepted. I have not managed to load any PNG images by following this guide, not even by using absolute paths in the css.

- [ ] This is a doc addition request.
- [ ] I have a fix to the document that I can paste below including example: input and output.

If you have a troubleshooting or support issue, use the following resources:

 - Ask OpenStack: http://ask.openstack.org
 - The mailing list: http://lists.openstack.org
 - IRC: 'openstack' channel on Freenode

-----------------------------------
Release: 12.0.3.dev13 on 2018-01-31 23:06
SHA: 08c86a64133ba1264c1981f17a8874ba2eee93bf
Source: https://git.openstack.org/cgit/openstack/horizon/tree/doc/source/admin/customize-configure.rst
URL: https://docs.openstack.org/horizon/pike/admin/customize-configure.html

[Chiemelie Carita Ndibe (caritajoe)]

This patch successfully changes the login page logo to the desired customised logo.