routie dev init since i didn't adhere to any proper guidance up until now

frontend/node_modules/eslint-plugin-unicorn/rules/prefer-array-index-of.js

@@ -0,0 +1,34 @@
+import simpleArraySearchRule from './shared/simple-array-search-rule.js';
+
+const indexOfOverFindIndexRule = simpleArraySearchRule({
+	method: 'findIndex',
+	replacement: 'indexOf',
+});
+
+const lastIndexOfOverFindLastIndexRule = simpleArraySearchRule({
+	method: 'findLastIndex',
+	replacement: 'lastIndexOf',
+});
+
+/** @type {import('eslint').Rule.RuleModule} */
+const config = {
+	create(context) {
+		indexOfOverFindIndexRule.listen(context);
+		lastIndexOfOverFindLastIndexRule.listen(context);
+	},
+	meta: {
+		type: 'suggestion',
+		docs: {
+			description: 'Prefer `Array#{indexOf,lastIndexOf}()` over `Array#{findIndex,findLastIndex}()` when looking for the index of an item.',
+			recommended: 'unopinionated',
+		},
+		fixable: 'code',
+		hasSuggestions: true,
+		messages: {
+			...indexOfOverFindIndexRule.messages,
+			...lastIndexOfOverFindLastIndexRule.messages,
+		},
+	},
+};
+
+export default config;