adding standalone lint command (#31)

While the frontend build operation includes linting, there was no
standalone step to lint and output what is wrong with formatting or
auto-fix code formatting issues.

react-frontend/package.json

@@ -23,6 +23,7 @@
 	"scripts": {
 		"start": "vite",
 		"build": "tsc && vite build",
+		"lint": "eslint --fix src/**/*.ts*",
 		"serve": "vite preview"
 	},
 	"eslintConfig": {