Load multiple JavaScript files in SharePoint JSLink
To load multiple JavaScript files in SharePoint JSLink, insert a pipe symbol between multiple JavaScript file links in the JSLink field of webpart’s properties.
JSLink Field Example:
~sitecollection/SiteAssets/jquery.min.js|~site/SiteAssets/my-custom-file.js
A piple symbo is a “|” without quotes
Source: https://egilhansen.com/2013/03/11/jslink-the-simple-way-to-add-and-load-multiple-javascript-files/