impl `From<&[T; N]>` for `Cow<[T]>`
Implement `From<&[T; N]>` for `Cow<[T]>` to simplify its usage in the following example.
```rust
fn foo(data: impl Into<Cow<'static, [&'static str]>>) { /* ... */ }
fn main() {
foo(vec!["hello", "world"]);
foo(&["hello", "world"]); // Error: the trait `From<&[&str; 2]>` is not implemented for `Cow<'static, [&'static str]>`
foo(&["hello", "world"] as &[_]); // Explicit convertion into a slice is required
}
```