feat: configure checkout and setup steps

Author: gladiuscode

.github/actions/setup/action.yml

@@ -0,0 +1,18 @@
+name: Setup
+description: Setup Node.js and install dependencies
+
+runs:
+  using: composite
+  steps:
+    - name: Use Node.js 18.x
+      uses: actions/setup-node@v4
+      with:
+        node-version: 18.x
+
+    - name: Enable corepack
+      run: corepack enable
+      shell: bash
+
+    - name: Install dependencies
+      run: yarn --immutable
+      shell: bash

.github/workflows/deploy.yml

@@ -8,5 +8,8 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - name: Echo
-        run: echo "Hello, world!"
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup
+        uses: ./.github/actions/setup