Update build to use nodejs instead of shell, add local spec support

Switch to node.js was made for better scripting support for things such as yaml consumption, general file IO, and better support for building the data file used to build the site.

As part of this patch, support for local files was added to pull specs already included in the project to use in the build.

The previous properties file was swapped to the repos.yaml which denotes all of the specs to be imported by the script, and adds support for custom display names to be used in the link text for the site.