ci: prettier check workflow (#90)

* ci: prettier check workflow

* refactor(ci): switch to manual npx call

* chore: add yml to validate-docs formatter

.github/workflows/validate-docs.yml

@@ -0,0 +1,44 @@
+name: validate-docs
+
+on:
+  push:
+    paths:
+      - '**/*.md'
+      - '**/*.json'
+      - '**/*.yml'
+      - '**/*.yaml'
+      - 'docs/**'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  prettier:
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        node: [20]
+
+    steps:
+      - name: Checkout 🛎
+        uses: actions/checkout@master
+
+      - name: Setup node env 🏗
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node }}
+          check-latest: true
+
+      - name: Cache node_modules 📦
+        uses: actions/cache@v2
+        with:
+          path: ~/.npm
+          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-
+
+      - name: Run format 💎
+        run: npx prettier --check --cache .