add prettier locally

pnpm-lock.yaml

@@ -7,6 +7,7 @@ specifiers:
   chart.xkcd: ^1.1.13
   iles: ^0.8.7
   pinia: ^2.0.27
+  prettier: ^2.8.1
   sass: ^1.56.2
   typescript: ^4.9.4
   vitest: ^0.25.8
@@ -22,6 +23,7 @@ devDependencies:
   '@islands/prism': 0.8.0
   '@islands/pwa': 0.9.1
   iles: 0.8.7_sass@1.56.2
+  prettier: 2.8.1
   sass: 1.56.2
   typescript: 4.9.4
   vitest: 0.25.8_sass@1.56.2
@@ -3868,6 +3870,12 @@ packages:
       picocolors: 1.0.0
       source-map-js: 1.0.2
 
+  /prettier/2.8.1:
+    resolution: {integrity: sha512-lqGoSJBQNJidqCHE80vqZJHWHRFoNYsSpP9AjFhlhi9ODCJA541svILes/+/1GM3VaL/abZi7cpFzOpdR9UPKg==}
+    engines: {node: '>=10.13.0'}
+    hasBin: true
+    dev: true
+
   /pretty-bytes/5.6.0:
     resolution: {integrity: sha512-FFw039TmrBqFK8ma/7OL3sDz/VytdtJr044/QUJtH0wK9lb9jLq9tJyIxUwtQJHwar2BqtiA4iCWSwo9JLkzFg==}
     engines: {node: '>=6'}