fix(eslintrc): configure eslint and run on codebase

.eslintrc.js

@@ -0,0 +1,9 @@
+/** @type {import('eslint').Linter.Config} */
+module.exports = {
+	extends: ["eslint:recommended", "plugin:@typescript-eslint/recommended"],
+	env: {
+		node: true,
+	},
+	// ignore the dist folder
+	ignorePatterns: ["dist", "*.config.js"],
+};

package.json

@@ -4,6 +4,7 @@
 	"scripts": {
 		"build": "webpack --mode=production",
 		"dev": "webpack --mode=development --watch",
+		"lint": "eslint --cache --cache-location ./node_modules/.cache/eslint .",
 		"release:cws": "chrome-webstore-upload upload --source=dist --auto-publish",
 		"release:amo": "web-ext-submit --source-dir dist",
 		"release": "VER=$(npx dot-json src/manifest.json version) run-s build version release:*",
@@ -14,6 +15,8 @@
 	"devDependencies": {
 		"@types/firefox-webext-browser": "^109.0.0",
 		"@types/webextension-polyfill": "^0.10.2",
+		"@typescript-eslint/eslint-plugin": "^6.4.1",
+		"@typescript-eslint/parser": "^6.4.1",
 		"chrome-webstore-upload-cli": "^2.2.2",
 		"copy-webpack-plugin": "^11.0.0",
 		"dot-json": "^1.3.0",

src/content-script.ts

@@ -5,7 +5,7 @@ import { parseGame } from "./parser";
 // On a message from the popup script, the content script parses the body of the
 // page and returns it to the client in JSON form.
 browser.runtime.onMessage.addListener(
-	(message, _sender, sendResponse: (response?: any) => void) => {
+	(message, _sender, sendResponse: (response?: unknown) => void) => {
 		if (message.message === "parse") {
 			const { game, error } = parseGame(document.body);
 			sendResponse({ game, error });