Yes it is now available. Archive will simply hide from project selection drop down. All the data and everything remains same and you can change archive setting anytime to start using project again. Steps to archive project.
- Select Project level settings from top right settings icon.
- Press Projects drop down, and select View All Projects.
- Press the folder icon on the widget of the project that you want to archive. This will archive the project. Please note: Only admins of the projects can do this action. If you are not admin then you will not be able to see these options.