Update project panel documentation on docs.swift.org

[rbenegal]

Is your feature request related to a problem? Please describe.
The extension has been updated with the project panel, but the documentation at https://docs.swift.org/vscode/documentation/userdocs/project-view still shows/refers to the old dependencies pane.

Describe the solution you'd like
The documentation should be updated to include screenshots and describe the functionality of the project panel.

Additional context
Can also possibly add a gif like on the https://docs.swift.org/vscode/documentation/userdocs/docc-live-preview page.