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.

Removes all the extra whitespaces at end of lines,
inside tags, and removes extra newlines

The configuration is currently only specified in CI, by moving it into
`.mdlrc` we get immediate feedback locally in supported editors.

To ensure `mdl` is available it's also added to the `Gemfile`, though
CI will still use the version installed in the `gitlab-docs-lint` image.

Update the installation link

See merge request gitlab-org/gitlab-ce!30489

Updating redirected links in the development, install, policy
raketasks and university dirs. Should now link to final
URL to avoid redirect hops

The consul docs are currently in the HA database section, but it should
be in it's own section.

Add relevant webcast to drive traffic and MQLs

See merge request gitlab-org/gitlab-ce!30236

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