Edited template.js to allow creating the map from a locally defined webmap in defaults.js- by inserting a property named "itemInfo". itemInfo would be constructed as a webmap JSON object as described in the section "Create a map using json" here: https://developers.arcgis.com/javascript/jshelp/intro_webmap.html
Added an example locally-defined webmap JSON object to defaults.js
Update README.md
Update README.md
Added a link in the README to the new LocalWebmap.md, which explains how
to define a webmap locally, rather than pulling from AGOL.