Function append`Const`

append<T>(item: T): (src: Iterable) => Iterable
Appends a single item to the end of the source iterable and returns a lazy iterable including the new item.

Curried version of _append.
Type Parameters
- T
  Element type produced by the source iterable and the appended value.
Parameters
- item: T
  Value appended as the final element of the resulting iterable.
Returns (src: Iterable) => Iterable
A deferred iterable yielding the original sequence followed by the appended item.
Example
```
const result = _append([1, 2], 3);
console.log([...result]); // [1, 2, 3]
```
or using the curried version:
```
const result = pipeInto([1, 2], append(3));
console.log([...result]); // [1, 2, 3]
```