docs(useAtIndex): fix typo chatAt -> charAt (#4363)

crates/biome_js_analyze/src/lint/nursery/use_at_index.rs

@@ -20,7 +20,7 @@ declare_lint_rule! {
     /// A more convenient way to achieve the same thing is to use the `at()` method with a negative index.
     /// To access the last element of an array or a string just write `array.at(-1)`.
     ///
-    /// This rule enforces the usage of `at()` over index access, `chatAt()`, and `slice()[0]` when `at()` is more convenient.
+    /// This rule enforces the usage of `at()` over index access, `charAt()`, and `slice()[0]` when `at()` is more convenient.
     ///
     ///
     /// ## Examples