install font face observer

package.json

@@ -20,6 +20,7 @@
     "@vueuse/router": "^10.3.0",
     "bulma": "^0.9.4",
     "date-fns": "^2.30.0",
+    "fontfaceobserver": "^2.3.0",
     "isomorphic-fetch": "^3.0.0",
     "markdown-it": "^13.0.2",
     "markdown-it-block-embed": "^0.0.3",
@@ -43,6 +44,7 @@
   "devDependencies": {
     "@babel/core": "^7.23.3",
     "@rushstack/eslint-patch": "^1.5.1",
+    "@types/fontfaceobserver": "^2.1.3",
     "@types/markdown-it": "^13.0.6",
     "@types/node": "^20.9.0",
     "@types/pouchdb-browser": "^6.1.5",