Ensure that all numbered lists use only 1. and no other numbers.
Also ensure that numbered lists use proper spacing.

Removing extra blank lines in docs that serve
no purpose, as well as some --- lines that also
are not needed.

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
will render as being in a code block too, even if not
meant to. This fixes all these issues, and cleans up
minor white space issues in install and integration docs

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

Also fixes instances in Markdown that broke the rule.

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

Add backticks around square brackets, or fix links, as necessary.

Linting rule not enabled for now
because tooling produces false
positives.