Explicitly add prettier to dev deps

package.json

@@ -20,7 +20,8 @@
     "build:demo": "vite build --mode demo",
     "preview": "vite preview",
     "serve": "vite preview",
-    "test": "vitest"
+    "test": "vitest",
+    "format": "prettier ./lib ./demo  -w -u"
   },
   "dependencies": {},
   "devDependencies": {
@@ -36,6 +37,7 @@
     "highlight.js": "^11.4.0",
     "jsdom": "^19.0.0",
     "postcss": "^8.4.5",
+    "prettier": "^2.5.1",
     "tailwindcss": "^3.0.15",
     "tributejs": "^5.1.3",
     "typescript": "^4.4.4",

yarn.lock

@@ -1523,6 +1523,11 @@ prelude-ls@~1.1.2:
   resolved "https://registry.yarnpkg.com/prelude-ls/-/prelude-ls-1.1.2.tgz#21932a549f5e52ffd9a827f570e04be62a97da54"
   integrity sha1-IZMqVJ9eUv/ZqCf1cOBL5iqX2lQ=
 
+prettier@^2.5.1:
+  version "2.5.1"
+  resolved "https://registry.yarnpkg.com/prettier/-/prettier-2.5.1.tgz#fff75fa9d519c54cf0fce328c1017d94546bc56a"
+  integrity sha512-vBZcPRUR5MZJwoyi3ZoyQlc1rXeEck8KgeC9AwwOn+exuxLxq5toTRDTSaVrXHxelDMHy9zlicw8u66yxoSUFg==
+
 pretty-format@^26.6.2:
   version "26.6.2"
   resolved "https://registry.yarnpkg.com/pretty-format/-/pretty-format-26.6.2.tgz#e35c2705f14cb7fe2fe94fa078345b444120fc93"