feat: option "--csvDelimiter <delimiter>"

[pgerlach]

A lot of CVS files are deliimited by ; instead of ,, and some softwares don't allow exporting using , as a separator.

This PR adds an optional --csvDelimiter option that can be used to specify the delimited we want. It defaults as comma.

Usage: githubCsvTools --csvDelimiter ';' ./myFileDelimitedByColons.csv