Use custom definitions for algorithms

[tymmale]

Hi! Great benchmark that you have here.

I noticed that the value of the --definitions argument is only used when listing all available algorithms. Correct me if I'm wrong, but I wanted to pass my own algorithm configurations, which are stored elsewhere, by using --definitions. This doesn't work because the program uses the default path ann-benchmarks/algorithms.

[maumueller]

Thanks @tymmale, this is indeed what --definitions was supposed to do. I'm waiting for the CI and will then merge this.