very slow compression (10s)
Hey! I don't know if this is really an "issue" per se, it's more of a curiosity that I thought you might be interested in.  I found a large cart and idly wondered how well shrinko8 would compress it, but it seemed to get caught in an infinite loop! but when I added some debugging `print`s, it wasn't actually stuck, it was just very slow:

```sh
> time shrinko8 '#amiquest-4' --bbs --count --no-count-tokenize
chars: 58092 89%
compressed: 15450 98.94%
```
I timed this a few times and got 10 or 11 seconds each time:
> 10.77s user 0.04s system 98% cpu 11.002 total
> 11.24s user 0.04s system 97% cpu 11.563 total
> 10.94s user 0.05s system 98% cpu 11.203 total

In comparison, a cart of mine only takes 2 seconds to compress; it also is very full of stringified sprite/map data.
```sh
> time shrinko8 '#thetower-0' --bbs --count --no-count-tokenize
chars: 27851 42%
compressed: 12498 80%
```
I timed it a few times:
> 1.15s user 0.03s system 81% cpu 1.439 total
> 1.11s user 0.04s system 89% cpu 1.290 total
> 1.17s user 0.03s system 89% cpu 1.347 total

-----

Maybe this is just a case of "yep, that's expected with the compression algorithm". (I tried amiquest with --fast-compression and it dropped down to 2 seconds as well) But I did think shrinko8 was stuck in an infinite loop, possibly a progress bar of some kind might be nice?