Fix date test examples

packages/string-templates/manifest.json

@@ -1196,7 +1196,7 @@
         "durationType"
       ],
       "numArgs": 2,
-      "example": "{{duration timeLeft \"seconds\"}} -> a few seconds",
+      "example": "{{duration 8 \"seconds\"}} -> a few seconds",
       "description": "<p>Produce a humanized duration left/until given an amount of time and the type of time measurement.</p>\n"
     }
   }

packages/string-templates/test/manifest.spec.js

@@ -1,6 +1,9 @@
 const fs = require("fs")
 const { processString } = require("../src/index.cjs")
 
+const tk = require("timekeeper")
+tk.freeze("2021-01-21T12:00:00")
+
 const manifest = JSON.parse(
   fs.readFileSync(require.resolve("../manifest.json"), "utf8")
 )