Add CI/CD pipeline and SDLC docs

.github/workflows/ci.yml

@@ -0,0 +1,67 @@
+name: CI
+
+on:
+  push:
+    branches: [develop, master]
+  pull_request:
+    branches: [develop]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+      
+      - name: Install dependencies
+        run: |
+          pip install ruff mypy
+          pip install -e ".[dev]"
+      
+      - name: Lint with ruff
+        run: ruff check src/
+      
+      - name: Type check with mypy
+        run: mypy src/ --ignore-missing-imports
+
+  test:
+    runs-on: ubuntu-latest
+    needs: lint
+    steps:
+      - uses: actions/checkout@v4
+      
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+      
+      - name: Install Stockfish
+        run: sudo apt-get update && sudo apt-get install -y stockfish
+      
+      - name: Install dependencies
+        run: pip install -e ".[dev]"
+      
+      - name: Run tests
+        run: pytest tests/ -v --tb=short
+
+  build:
+    runs-on: ubuntu-latest
+    needs: test
+    steps:
+      - uses: actions/checkout@v4
+      
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      
+      - name: Build Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: false
+          tags: shellmate:${{ github.sha }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max