<!--IssueSummary start--> <details> <summary> Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards. </summary> - [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=471935) </details> <!--IssueSummary end--> One of our [customers](https://gitlab.zendesk.com/agent/tickets/548444) is requesting to have `Containerfile` (`*.Containerfile`) files have syntax highlighting when viewed via the editor in the UI. `Containerfile` uses the same syntax as a `Dockerfile`. ### Proposal Enable syntax highlighting for `Containerfile`.