Enable PseudoElement in scss-lint

.scss-lint.yml

app/assets/stylesheets/framework/dropdowns.scss

app/assets/stylesheets/framework/lists.scss

app/assets/stylesheets/framework/timeline.scss

app/assets/stylesheets/framework/typography.scss

app/assets/stylesheets/pages/diff.scss

app/assets/stylesheets/pages/pipelines.scss

app/assets/stylesheets/pages/profile.scss

app/assets/stylesheets/pages/projects.scss

app/assets/stylesheets/pages/search.scss

app/assets/stylesheets/pages/ui_dev_kit.scss

app/assets/stylesheets/print.scss