Convert to indentation-based blocks

Much like Python.

Currently, we have:

```py
i = -1;
while (i = i + 1) < n {
j = i;
while (j = j + 1) < n {
part1 = rep[i] * rep[j] if rep[i] + rep[j] == 2020;

k = j;
while (k = k + 1) < n {
part2 = rep[i] * rep[j] * rep[k] if rep[i] + rep[j] + rep[k] == 2020;
};
};
};
```

But it should become the following (no curly braces, no required semicolons):

```py
i = -1
while (i = i + 1) < n:
j = i
while (j = j + 1) < n:
part1 = rep[i] * rep[j] if rep[i] + rep[j] == 2020

k = j
while (k = k + 1) < n:
part2 = rep[i] * rep[j] * rep[k] if rep[i] + rep[j] + rep[k] == 2020
```