Deprecate old TW labels, replace some with scoped labels.

Issue Description

The technical writing team now has the following scoped labels to describe types of work:

• docsfeature
• docsfix
• ~"docs::housekeeping"
• docsimprovement
• ~"docs::new"
• ~"docs::revamp"

When someone wants to raise an Epic, Issue, or MR, there is ambiguity between some of these and:

• ~"docs-fix"
• ~"docs:fix"
• ~"docs:new"
• ~"docs:revamp"

It would seem simple to have these converted to their scoped equivalent.

We might also want to take a look at, and possibly deprecate some of the following:

• ~"docs-article"

• ~"docs-comm-writer"

• docs-comments

• docs-discussion

• docs-missing

• ~"docs-not-in-production"

• docs-only

• ~"docs-priority"

• docs-review

• ~"docs-structure"

• docs-technical-debt

• ~"docs-todo"

• ~"docs-topic"

• ~"docs-update"

• ~"docs-write"

• ~"docs:OKR18Q3"

• ~"docs:discussion"

• ~"docs:other"

This list doesn't include some gitlab-com-scoped labels like: https://gitlab.com/groups/gitlab-com/-/labels?utf8=✓&subscribed=&search=docs

WDYT, @gl-docsteam