Link in bundler not working.

[This url](https://github.com/kparc/ref/blob/master/bundler/download.js#L16) seems to not have anything there, which leads to an error during npm install:
```
$ node bundler/download.js  
TypeError: data.filter is not a function
    at /Users/XXXX/K/kparc/ref/bundler/download.js:20:24
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
$
```