Many code blocks are 4spaced, and they render in GitLab
without coloring as a result, even though they are
fenced with a language label. If in a list, other items
woll render as being in a code block too, even if not
meant to. This fixes all these issues, and cleans up
minor whitespace issues in /user, /security, /ssh
and /migrate_ci_to_ce docs.

Doc for "Allow a template in a namespace which is out of the
hierarchy of the Group owning the template"

This updates redirected links in integration, update, user
and workflow dirs. Should now link to final URLs to avoid
redirect hops

Previously, we used brackets to denote the tier badges,
but this made Kramdown, the docs site Markdown renderer,
show many warnings when building the site. This is now
fixed by using parentheses instead of square brackets.

This was caused by [PREMIUM] looking like a link to
Kramdown, which couldn't find a URL there.

See:
- https://gitlab.com/gitlab-com/gitlab-docs/merge_requests/484
- https://gitlab.com/gitlab-org/gitlab-ce/issues/63800

Adjusts asterisks to hyphens in assorted docs to allow lint rule to pass

Signed-off-by: NRémy Coutable <remy@rymai.me>

Also adds and one linting rule
and makes project conform to it.

This enables terminals for group and project level clusters.
Previously there was no way to determine which project (and
therefore kubernetes namespace) to connect to, moving this
logic onto Environment means the assoicated project can be
used to look up the correct namespace.

Now MySQL is no longer supported, we need to change the docs

Any resources created while the cluster was managed
will be untouched, allowing users to set/unset this
flag as they please.

Signed-off-by: NRémy Coutable <remy@rymai.me>

Updates documentation to reflect that SAML can now
be used to sign into the GitLab instance, instead of
just updating group membership.

So we can add detailed information, and also point to SSOT