web/slide_puzzle: use hosted font for Plaster

web/slide_puzzle/web/assets/FontManifest.json

@@ -11,7 +11,7 @@
     "family": "Plaster",
     "fonts": [
       {
-        "asset": "plaster.woff2"
+        "asset": "https://fonts.gstatic.com/l/font?kit=DdTm79QatW80eRh4EitJPNLPUrnLdNiMw9JVKCON&skey=6748ccde38e8a5e5&v=v10"
       }
     ]
   }

web/slide_puzzle/web/assets/readme.md

@@ -0,0 +1,15 @@
+### Material Icon font
+
+Via https://google.github.io/material-design-icons/#icon-font-for-the-web
+
+Via https://fonts.googleapis.com/icon?family=Material+Icons
+
+### Plaster font
+
+Via https://fonts.google.com/specimen/Plaster
+
+Via https://fonts.googleapis.com/css?family=Plaster&text=0123456789
+
+*Note `text=` includes only the used characters – 0-9.*
+
+*HT to https://twitter.com/csswizardry/status/1139435442506469376*