chore: add declaration file generation

Author: devsheva

package.json

@@ -7,6 +7,7 @@
 		"url": "https://github.com/devsheva"
 	},
 	"main": "dist/logger.js",
+	"types": "dist/logger.d.ts",
 	"description": "A simple logging library",
 	"devDependencies": {
 		"@vitest/coverage-v8": "^2.0.5",

tsconfig.build.json

@@ -1,5 +1,8 @@
 {
     "extends": "./tsconfig.json",
+    "compilerOptions": {
+        "declaration": true
+    },
     "exclude": [
         "spec/**/*.ts",
         "test/**/*.ts"