Install biome for linting and formatting

.vscode/extensions.json

@@ -0,0 +1,3 @@
+{
+  "recommendations": ["biomejs.biome"]
+}

biome.json

@@ -0,0 +1,34 @@
+{
+  "$schema": "https://biomejs.dev/schemas/1.9.3/schema.json",
+  "vcs": {
+    "enabled": false,
+    "clientKind": "git",
+    "useIgnoreFile": false
+  },
+  "files": {
+    "ignoreUnknown": false,
+    "ignore": []
+  },
+  "formatter": {
+    "enabled": true,
+    "indentStyle": "space"
+  },
+  "organizeImports": {
+    "enabled": true
+  },
+  "linter": {
+    "enabled": true,
+    "rules": {
+      "recommended": true,
+      "style": {
+        "noNonNullAssertion": "off"
+      }
+    }
+  },
+  "javascript": {
+    "formatter": {
+      "quoteStyle": "double",
+      "trailingCommas": "none"
+    }
+  }
+}

package.json

@@ -6,13 +6,7 @@
   "types": "./dist/index.d.ts",
   "exports": "./dist/index.js",
   "sideEffects": false,
-  "files": [
-    "dist",
-    "src",
-    "package.json",
-    "LICENSE.txt",
-    "README.md"
-  ],
+  "files": ["dist", "src", "package.json", "LICENSE.txt", "README.md"],
   "license": "MIT",
   "description": "A JMAP client library for Node.js and the browser.",
   "repository": {
@@ -25,9 +19,11 @@
   },
   "scripts": {
     "preversion": "tsup",
-    "build": "tsup"
+    "build": "tsup",
+    "check": "biome check --write ."
   },
   "devDependencies": {
+    "@biomejs/biome": "1.9.3",
     "@types/node": "20.8.4",
     "tsup": "7.2.0",
     "tsx": "3.13.0",