Initialize git-contribution-graph project with Docker setup, environment configuration, and core functionality for merging contributions from GitHub, GitLab, and Gitea into an SVG heatmap.

docker-compose.yml

@@ -0,0 +1,23 @@
+services:
+  graph:
+    build: .
+    container_name: git-contribution-graph
+    restart: unless-stopped
+    ports:
+      - "8080:8080"
+    environment:
+      APP_ENV: prod
+      APP_DEBUG: "0"
+      APP_SECRET: "${APP_SECRET}"
+    volumes:
+      - cache:/app/var/cache
+      - logs:/app/var/log
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:8080/health"]
+      interval: 30s
+      timeout: 5s
+      retries: 3
+
+volumes:
+  cache:
+  logs: