Editing more than a single file using the GitLab interface can feel laborious because each file must be edited one by one, requiring at least one commit for each edited file. This makes contributing changes to multiple files, be they markdown or source code, through the GitLab interface difficult. We want to make it easy for everyone to collaborate. Removing barriers will help people contribute more than fixes to typos and dead links, but allow people to contribute larger changes, offer more comprehensive code review suggestions and more all from the web User stories: - When I am improving the GitLab handbook I want to be able to view and edit multiple files simultaneously, so that I am free to focus on making clear consistent changes without needing to hold a list of file by file changes in my head. I don't think file by file, but change by change where each change my span multiple files. - When I am reviewing a merge request I want to be able to review changes in greater detail and context so that I can give more meaningful feedback to my colleagues. I don't want to be dissuaded from giving great feedback by the inconvenience of switching context in my local environment to review the change in full detail.