Browse page improvements

• For now please add "To browse a subset of artifacts that match your interest, please choose a featured category to explore. " instead of the lorem text as intro.
• Do we have any images for the grey blocks? If not, maybe comment it out and have the card without images for now
• Link the 5 categories to their respective index (eg /proveniences/ for "Proveniences"
• Pluralize "Provenience"