Hash level redirects functionality

[bencodezen]

Requirements

• Figure out strategy for hash level redirects implementation
• Determine maintenance strategy

Background

// /foo#hello -> /bar#hello
//
// For these cases where a section on one page has
// moved to a perhaps differently-named section on
// another page, we need this.

[bencodezen]

For redirects, we should be using Netlify redirects at this point.

If this becomes a bigger issue, will open another issue; but don't think it's worth keeping this open at this time until that comes to pass.