Making development patterns more efficient with ZSH

A common pattern I find myself encountering is converting a CSV to a projected GeoJSON as described here.

That entails 3 steps, and I’d like to get it down to the following:

GEOIFY {file} {originalProjection} {newProjection} =
    csv2geojon {file.csv} > {file.geojson} &&
    ogr2ogr 
        -F geojson 
        -s_srs epsg:{originalProjection} 
        -t_srs epsg:{newProjection}
        {reprojectedFile.geojson} {file.geojson}

If anyone has any good resources on how to create functions and use variables with ZSH (which is what I think I need to do this) that would be beautiful. I must be using the wrong vocabulary, because my googling hasn’t yielded anything so far.

As always, thanks!