[Functions] add example for d style, static array, varatic functions

[dlangBugzillaToGithub]

crazymonkyyy reported this on 2023-10-28T17:35:33Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=24205

Description

```
auto swizzle(T,I,size_t N)(T array,I[N] indexs...){
  ...
}

unittest{
    int[] i=[1,2,3,4,5];
    i.swizzle(0,4,2);    
}
```

I found it hard to get this working