   Returns the path to the file that defines the current project.
 
   The majority of the time, it will point to a `mix.exs` file.
-  Returns nil if not inside a project.
+  Returns `nil` if not inside a project.
   """
   @doc since: "1.13.0"
   @spec project_file() :: binary | nil

  The returned path will be expanded.

  ## Examples

      Mix.Project.consolidation_path()
      #=> "/path/to/project/_build/dev/lib/my_app/consolidated"

  ## Options

    * `:depth` - only returns dependencies to the depth level,
      a depth of `1` will only return top-level dependencies
    * `:parents` - starts the dependency traversal from the
      given parents instead of the application root

