Add GitHub Actions for tool setup and code quality checks

Introduced new GitHub Actions workflows for installing necessary tools (PNPM, Node.js) and dependencies. Also added jobs to perform code quality checks using Astro and ESLint to ensure code quality and standards.

.github/actions/install/action.yml

@@ -0,0 +1,18 @@
+name: Install Tools & Dependencies
+description: Installs pnpm, Node.js & package dependencies
+
+runs:
+  using: composite
+  steps:
+    - name: Setup PNPM
+      uses: pnpm/action-setup@v3
+
+    - name: Setup Node
+      uses: actions/setup-node@v4
+      with:
+        node-version: 18
+        cache: pnpm
+
+    - name: Install dependencies
+      run: pnpm install
+      shell: bash

.github/workflows/ci.yml

@@ -0,0 +1,43 @@
+name: Code Quality Check
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name == 'pull_request_target' && github.head_ref || github.ref }}
+  cancel-in-progress: true
+
+env:
+  NODE_OPTIONS: "--max_old_space_size=4096"
+
+jobs:
+  astrocheck:
+    name: Check for type issues with astro check
+    runs-on: ubuntu-latest
+    env:
+      FORCE_COLOR: true
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install Tools & Dependencies
+        uses: ./.github/actions/install
+
+      - name: Run Astro Check
+        run: pnpm run check
+
+  eslint:
+    name: Check for code issues with ESLint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install Tools & Dependencies
+        uses: ./.github/actions/install
+
+      - name: Run ESLint
+        run: pnpm run lint:eslint