Adds MD010 (Hard tabs), MD012 (blank lines), MD029 (ordered
list prefix), MD030 (spaces after list markers), and fixes
remaining docs that were failing these tests

Remove unneeded trailing whitespace in lines in
/development /ci /api and /administration docs.

Code blocks should not be spaced 4 times, as this will
prevent the code from being colored. They should
also be spaced the same as the lists they are a part
of, to make reading easier.

Includes changes to the Vue container registry component to support
the display of an empty message and error message when invalid
characters are found in the group, project or branch name.

repositories/index.html.haml has been changed to remove the content
and place into Vue component.

* The container registry needs a compatibility setting enabled for older
docker clients. This will document how to enable the setting for
omnibus and source installations.

For the sake of consistency, removes any extraneous
consecutive blank lines from the doc suite.

The container registry requires the `auth` config to be set up properly
or users will be able to download images that they are not authorized to
do so.

For example https://gitlab.com/gitlab-org/gitlab-runner/issues/3652

Closes https://gitlab.com/gitlab-org/omnibus-gitlab/issues/1433

[ci skip]

[ci skip]

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/18441

This reverts commit 3e991230.