Add .dockerignore to prevent secrets from being copied into image

.dockerignore

@@ -0,0 +1,25 @@
+# Environment and secrets
+.env
+.env.*
+!.env.example
+
+# Dependencies
+node_modules
+
+# Git
+.git
+.gitignore
+
+# Development files
+*.log
+npm-debug.log*
+.DS_Store
+
+# Test files
+test-endpoints.js
+*.test.js
+__tests__
+
+# IDE
+.vscode
+.idea