Add a "-j" flag?

Sometimes I run out of memory when running ncclimo in time series split mode with a long list of variables. I can solve this using the -j flag in ncclimo, but I wish I could do so through zppy somehow! Great tool.

The issue concerns zppy’s time-series split mode and its use of ncclimo; start by tracing how zppy handles options and invokes ncclimo. No file or test is named, so locate the relevant entry point before checking how the -j value should be exposed. Done means zppy can pass -j through for this workflow without affecting other modes.

Written by the indexing model from the issue text.