Write github-changelog blog

Write blogpost about Github changelog: https://github.com/uberVU/github-changelog/
Demo: http://ubervu.github.io/github-changelog/

Draft doc: https://docs.google.com/a/ubervu.com/document/d/1SQb-qkcXc9tYKP7e9JZYrumzSqCeogzy7gzvIOCt9UY/edit#

- [ ] Put blog post in Markdown
- [ ] Put live
- [ ] Share it