Add node modules and new code for release (#57)

Co-authored-by: taakleton <taakleton@users.noreply.github.com>

node_modules/underscore/cjs/_unescapeMap.js

@@ -0,0 +1,7 @@
+var invert = require('./invert.js');
+var _escapeMap = require('./_escapeMap.js');
+
+// Internal list of HTML entities for unescaping.
+var unescapeMap = invert(_escapeMap);
+
+module.exports = unescapeMap;