CB-13305: Docs can't build because of ES6 code use
CB-13305: Docs can't build because of ES6 code use

Updated `linkRef` function to use `var` and ES5 functions instead of
`let` and arrow functions.

purplecabbage/cordova-docs,shazron/cordova-docs,shazron/cordova-docs,apache/cordova-docs,purplecabbage/cordova-docs,purplecabbage/cordova-docs,stevengill/cordova-docs,stevengill/cordova-docs,shazron/cordova-docs,apache/cordova-docs,apache/cordova-docs,stevengill/cordova-docs,apache/cordova-docs,stevengill/cordova-docs,shazron/cordova-docs,purplecabbage/cordova-docs