add notice to new rule and improve test

docs/rules/prefer-code-point.md

@@ -1,5 +1,9 @@
 # Prefer `String#codePointAt(…)` over `String#charCodeAt(…)` and `String.fromCodePoint(…)` over `String.fromCharCode(…)`
 
+✅ The `"extends": "plugin:unicorn/recommended"` property in a configuration file enables this rule.
+
+💡 Some problems reported by this rule are manually fixable by editor [suggestions](https://eslint.org/docs/developer-guide/working-with-rules#providing-suggestions).
+
 Unicode is better supported in [`String#codePointAt()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/codePointAt) and [`String.fromCodePoint()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/fromCodePoint).
 
 - [Different between `String.fromCodePoint()` and `String.fromCharCode()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/fromCodePoint#compared_to_fromcharcode)

test/package.mjs

@@ -236,8 +236,8 @@ test('Every rule has a doc with the appropriate content', t => {
 		// Ensure that expected notices are present in the correct order.
 		let currentLineNumber = 1;
 		for (const expectedNotice of expectedNotices) {
-			t.is(documentLines[currentLineNumber], '', `has blank line before ${expectedNotice} notice`);
-			t.is(documentLines[currentLineNumber + 1], MESSAGES[expectedNotice], `includes ${expectedNotice} notice`);
+			t.is(documentLines[currentLineNumber], '', `${ruleName} has blank line before ${expectedNotice} notice`);
+			t.is(documentLines[currentLineNumber + 1], MESSAGES[expectedNotice], `${ruleName} includes ${expectedNotice} notice`);
 			currentLineNumber += 2;
 		}