Add redirects to links with campaigns

[rmartinezduque]

We have some links on our social channels like this one, https://frontity.org/get-started, redirected to https://frontity.org/?utm_source=twitter&utm_medium=bio&utm_campaign=v1-launch (a link to our website with UTM parameters) The first link it's shorter and more convenient for the social media profiles/descriptions.

Observed behavior
Links like https://frontity.org/get-started show now a 404 page.

Possible solution
@SantosGuillamot suggested this: I guess we'll need to modify the now.json and add some routes to do this until the server extensibility is ready.