Replace copy from Excel file

[brandongregoryscott]

Based off of the work done in #3, update the existing command to handle Excel files or add a new command to read an Excel file and pass along the contents to the property replacement logic that currently exists.

A quick search lead me to https://www.npmjs.com/package/read-excel-file which may be a viable option for deserializing an Excel file. Ideally there's little to no configuration necessary for this, similar to the JSON command - we should expect two columns (first being the keys and second being the values).