chore(i18n): Introduce new string literal

Author: oliversalzburg

packages/userscript/source/i18n/en.json

@@ -15,6 +15,7 @@
   "act.refineTCs": "Refined {0} time crystals",
   "act.refineTears": "Refined tears into BLS",
   "act.sacrificeAlicorns": "Sacrificed {0} alicorns",
+  "act.sacrificeUnicorns": "Sacrificed {0} unicorns",
   "act.sun.discover": "Kittens have discovered {0}",
   "act.sun.discovers": "Kittens have discovered {0} {1} times",
   "act.time.skip": "Kittens combust a time crystal, {0} years skipped!",