Adding icons related to markdown editor (!561) · Merge requests · GitLab.org / gitlab-svgs · GitLab

Adding new icons for WYSIWYG editor toolbar.

The new functionality will need the following icons

heading
strikethrough
underline
list indent
list outdent

To view in Figma https://www.figma.com/file/RhYal9t4OZk7IeYsSvEHpW/WYSIWYG-markdown-editor-214559?node-id=36%3A46457