Docs feedback: Fix tutorial

• [x ] Start this issue's title with Docs: or Docs feedback:.

Problem to solve

The tutorial Contribute code with the Web IDE asks for a file to be edited. The file, app/views/profiles/preferences/show.html.haml, does exist, but the string in the tutorial, "Customize the color of GitLab", is not there anymore. The link to that file is here.

The tutorial needs to be updated so that a user can successfully follow it.

Further details

https://docs.gitlab.com/development/contributing/first_contribution/contribute-web-ide/

Implementation plan

Try to complete the tutorial. Create the file or change the tutorial so it works.

Imagine the frustration of a first time user. Use that frustration to improve the tutorial.

Who can address the issue

Other links/references