New url for swapi-graphql redirects

There's will be a new build for swapi-graphql at netlify once graphql/swapi-graphql#162 is merged, we can merge this to take it live 🌍 

I'm pretty sure the order of the last two rules will be fine. If the last one doesn't work, it will still work

```
/swapi-graphql/graphql https://swapi-graphql.netlify.com/.netlify/functions/index 200
```
this just 200 redirects (non permanent?) which essentially is netlify terms for what nginx is a proxy_path

so this will just make `graphiql.org/swapi-graphql/graphql` an alias for the lambda endpoint. see the PR's develop preview before it's merged if you want to see that default lambda path in action for yourself

Author: acao

site/_redirects

@@ -1,2 +1,3 @@
-/swapi-graphql  https://graphql.github.io/swapi-graphql/   200
-/swapi-graphql/* https://graphql.github.io/swapi-graphql/:splat   200
+/swapi-graphql  https://swapi-graphql.netlify.com   200
+/swapi-graphql/* https://swapi-graphql.netlify.com/:splat   200
+/swapi-graphql/graphql https://swapi-graphql.netlify.com/.netlify/functions/index 200