Enable 301 Redirects on about.gitlab.com for Marketing

It's critical for Marketing's lead gen plans (which feed into our top line IACV revenue goals) that we improve our SEO on about.gitlab.com.

The site is a static site built by Middleman, which cannot support 301 redirects.

We need to provide...

1. A source controlled format for redirects that anyone can contribute to, and that can be validated/tested in CI to the extent possible
2. A server that can respond to requests appropriate based on these redirects, and still serve the static site for requests that make it through.

Other considerations

• This server might be an origin service for a CDN like Fastly, rather than a front line web service
• If there is a way we can empower Todd and his team to take over full ownership of this (and future issues) we should consider that too

@glopezfernandez Feel free to delegate to @dawsmith or @northrup or whomever is the right person to execute.

Thanks!

CC @twbarr