Implement a better pattern for linking the bootstrap css from CDN

[jsoules]

PR #16 fixes most of the styling issues up to this point, by linking the full bootstrap.css file from the content delivery network into the index.css file. While this works, it's probably not optimal/optimized, either to have them as the same file, or to be linking a CDN file directly into our own CSS (since this probably affects caching, freshness of the version, etc.)

See if there's a better practice about how to do this.