Create GitLab blog repository
## Problem to solve
With a static site generator, you create all of your pages at once. And even though the process is fast, it scales linearly with the amount of content. The GitLab website (`about.gitlab.com`) is built with Middleman and generates about 14,000 files everytime the site is deployed. This results in the following issues:
* Local development of about.gitlab.com is slow and cumbersome
* The CI/CD process takes over an hour to deploy
* Middleman takes approximately 30 minutes to build the production website alone
* Deploying time-sensitive content is hindered by the long deployment process
* If the pipeline is broken, it prevents any updates being deployment
## Proposal
Let's update the blog infrastructure so it builds independently from the rest of the site.
## What does success look like, and how can we measure that?
* [ ] Fast live reloading of content and frontend assets during local development
* [ ] A 60% reduction in Middleman build time for `about.gitlab.com/blog` (less than 10mins)
* [ ] Reduce CI/CD pipeline time by 50% or more for `about.gitlab.com/blog`
* [ ] Enable blog to deploy independently of handbook/marketing pipeline
epic