Add link to root directory in file path breadcrumbs UI

Created by: olafurpg

Feature request description

When browsing a file, you click on a button to open the root directory of the repository and you click on a link to open a subdirectory.

It would be nice if there was a link to the root directory that was consistent with the links to the subdirectories.

Is your feature request related to a problem? If so, please describe.

It may be difficult for users to discover the button to the root directory. For example, https://twitter.com/willnorris/status/1435649914814418944

Additional context

For inspiration, GitHub file breadcrumbs include a link to the root directory