bash script for gorse playground doesn't work on macOS

[ubrmnsh]

Please answer these questions before submitting your issue. Thanks!

Gorse version
v0.4.14

Describe the bug
the given bash script to create a playground doesn't work

To Reproduce
on a macOS Ventura, paste and enter this
curl -fsSL https://gorse.io/playground | bash

Expected behavior
it would have generated the playground and downloaded the datasets

Additional context
while going through bash script i found out that
PLAYGROUND_BIN=./gorse-in-one_${OS}_${ARCH}
in my case, this variable doesn't need OS and ARCH info, as downloaded file named as gorse-in-one
so if i remove the OS and ARCH, it works fine.

[zhenghaoz]

Thanks. It will be fixed in #94