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

Many small fixes to api docs which were merged from EE to CE,
and tables cleaned up, as noted in issue
https://gitlab.com/gitlab-org/gitlab-ce/issues/64072

Squashing a few commits and continuing work
on merging the 12 api docs that have not
been ported to CE yet.

Changes migration and all other places the attribute is used

Adds an instance setting to limit display of time tracking
values to hours only

fix #58023

docs for adding Saturday for first day of the week
add related settings for Saturday as first day of the week
firstDayOfWeek: Use enumeration, replace day's numbers with corresponding names
make some variables lowercase (follow camelCase)
add CHANGELOG entry

Author:    haghighi_ahmad <haghighi.ahmad@gmail.com>

modified:   app/assets/javascripts/pages/users/activity_calendar.js
modified:   app/helpers/preferences_helper.rb
new file:   changelogs/unreleased/58023-add-Saturday-to-localization-first-day-of-the-week.yml
modified:   doc/api/settings.md
modified:   doc/user/profile/preferences.md
modified:   locale/gitlab.pot
modified:   spec/helpers/preferences_helper_spec.rb

Cached markdown version is composed both from global and local
markdown version. This allows admins to bump version locally when
needed (e.g. when external URL is changed).