`jq' is here to help us modify .json files.

The tool jq (https://github.com/stedolan/jq) is so awesome!!
Define variables.
Dealing with the `first-run' target.
Dealing with the `install-mods' target.
Update the list of things needed to pack.
Rename the list to `packing-list'.
Dealing with the new location of the `mods' folder of ModLoader.