If you want to share the whole workspace project, including folders, then this is only possible over a team invitation.
Within the Project, do the following steps:
Click the team Icon in the powerbar.
Fill in the email address of your team member.
Insert a message. (Not obligatory).
Set a role for your colleague. (Reviewer, Editor or Owner). You can give him permissions to view your Style Guide by activating the switcher.
You can grant access from a date to a date. Click on Temporary access to set the date details.
Click invite and a mail will send to your team member.