feat(metadata): Add YAML check/format npm scripts.

app/.gitignore

@@ -1 +1,2 @@
 build/
+node_modules/

app/.prettierrc.js

@@ -0,0 +1,3 @@
+module.exports = {
+    endOfLine: "auto",
+};

app/package-lock.json

@@ -0,0 +1,36 @@
+{
+  "name": "zmkfirmware",
+  "version": "1.0.0",
+  "lockfileVersion": 2,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "zmkfirmware",
+      "version": "1.0.0",
+      "license": "MIT",
+      "devDependencies": {
+        "prettier": "^2.4.0"
+      }
+    },
+    "node_modules/prettier": {
+      "version": "2.4.0",
+      "resolved": "https://registry.npmjs.org/prettier/-/prettier-2.4.0.tgz",
+      "integrity": "sha512-DsEPLY1dE5HF3BxCRBmD4uYZ+5DCbvatnolqTqcxEgKVZnL2kUfyu7b8pPQ5+hTBkdhU9SLUmK0/pHb07RE4WQ==",
+      "dev": true,
+      "bin": {
+        "prettier": "bin-prettier.js"
+      },
+      "engines": {
+        "node": ">=10.13.0"
+      }
+    }
+  },
+  "dependencies": {
+    "prettier": {
+      "version": "2.4.0",
+      "resolved": "https://registry.npmjs.org/prettier/-/prettier-2.4.0.tgz",
+      "integrity": "sha512-DsEPLY1dE5HF3BxCRBmD4uYZ+5DCbvatnolqTqcxEgKVZnL2kUfyu7b8pPQ5+hTBkdhU9SLUmK0/pHb07RE4WQ==",
+      "dev": true
+    }
+  }
+}

app/package.json

@@ -0,0 +1,23 @@
+{
+  "name": "zmkfirmware",
+  "version": "1.0.0",
+  "description": "ZMK Firmware tooling",
+  "private": "true",
+  "scripts": {
+    "prettier:check": "prettier --check boards/**/*.yml",
+    "prettier:format": "prettier --write boards/**/*.yml"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/zmkfirware/zmk.git"
+  },
+  "author": "ZMK Contributors",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/zmkfirware/zmk/issues"
+  },
+  "homepage": "https://zmk.dev/",
+  "devDependencies": {
+    "prettier": "^2.4.0"
+  }
+}