build: migrate to eslintrc.js

This allows us to simplify it and remove duplicities.

.eslintrc.js

@@ -0,0 +1,31 @@
+const commonExtends = [
+    "plugin:@typescript-eslint/recommended",
+    "plugin:react/recommended",
+    "plugin:react-hooks/recommended",
+    "plugin:prettier/recommended",
+];
+
+module.exports = {
+    parser: "@typescript-eslint/parser",
+    plugins: ["@typescript-eslint"],
+    extends: commonExtends,
+    overrides: [
+        {
+            files: ["./src/**/*.ts", "./src/**/*.tsx"],
+            parserOptions: {
+                project: ["./tsconfig.json"],
+            },
+            extends: [
+                ...commonExtends,
+                "plugin:@typescript-eslint/recommended-type-checked",
+                "plugin:@typescript-eslint/strict",
+            ],
+        },
+    ],
+    settings: {
+        react: {
+            version: "detect",
+        },
+    },
+    ignorePatterns: "demo",
+};