docs: Fix entries() return type to specify 2-element tuple

Author: avoidwork

docs/API.md

@@ -232,7 +232,7 @@ console.log(cache.entries(["c", "a"]));
 | ------ | ---------- | ---------------------------------- |
 | `keys` | `string[]` | Optional specific keys to retrieve |
 
-**Returns:** `Array<(string|*)[]>` - Array of key-value pairs
+**Returns:** `[string, *][]` - Array of 2-element tuples [key, value]
 
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