v0.13.1

🐛 Bug Fix

• @theme-ui/css
  • css: Make background a theme-aware property #2056 (@lachlanjc)

Authors: 4

• @dependabot[bot]
• Akash (@appsparkler)
• Lachlan Campbell (@lachlanjc)
• Piotr Monwid-Olechnowicz (@hasparus)