Assignment broadcasting
Currently this is a bit unwieldly

```Nim
import ../src/arraymancer, sequtils, random, typetraits

const
  rows = 7
  cols = 7
  channels = 70

# const k = 3

proc hex_distance(r1, c1, r2, c2: int): int =
  return (abs(r1 - r2) + abs(r1 + c1 - r2 - c2) + abs(c1 - c2)) div 2


proc generate_neighbors(): Tensor[int] =
  result = newTensor[int]([rows, cols, 7, 2])
  for r1 in 0 ..< rows:
    for c1 in 0 ..< cols:
      result[r1, c1, 0, 0..1] = [[[[r1, c1]]]]

echo generate_neighbors()
```