Fill 
by キリサメ qianxi @qianxi0410
`Fill`, a common JavaScript function, now let us implement it with types.
`Fill`, as you can see,`Fill` accepts four types of parameters, of which `T` and `N` are required parameters, and `Start` and `End` are optional parameters.
The requirements for these parameters are: `T` must be a `tuple`, `N` can be any type of value, `Start` and `End` must be integers greater than or equal to 0.
```ts
type exp = Fill<[1, 2, 3], 0> // expected to be [0, 0, 0]
```
In order to simulate the real function, the test may contain some boundary conditions, I hope you can enjoy it :)
