chore: include only code into npm package

This excludes directories docker, examples and tests from a package that is published with npm publish

Author: php-coder

package.json

@@ -26,6 +26,9 @@
     "start": "node src/index.js",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
+  "files": [
+    "src/**"
+  ],
   "dependencies": {
     "ejs": "~3.1.3",
     "js-yaml": "~3.14.0"