404 Pages on Collections

[khinshankhan]

Abstracted the logic in the resources' 404 page to work on any given collection. Implemented it for the tech spotlights. It should be easy enough to add the special 404 to a new collection if one appears as well.

A couple of notes:

• Not sure if the threshold (number of single characters edits needed to consider a url a viable candidate) is too high for tech spotlights (since tech spotlights have the extra what-is-)
• We may need to refactor gatsby-node.js's onCreatePage later to use a switch
• I tried to use proper types, but those may require some review :sweat_smile:

[veksen]

Nice! Could you run npm run format and npm run lint:fix on the code?