docs: change order of setup node and pnpm (#129)

Author: hyesungoh

README.md

@@ -115,18 +115,18 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Install Node.js
-        uses: actions/setup-node@v4
-        with:
-          node-version: 20
-          cache: 'pnpm'
-
       - uses: pnpm/action-setup@v4
         name: Install pnpm
         with:
           version: 8
           run_install: false
 
+      - name: Install Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: 'pnpm'
+
       - name: Get pnpm store directory
         shell: bash
         run: |