Move configuration to env bindings

[evanderkoogh]

Allows you to keep the code the same and configure it via the dashboard bindings screen.

[samouri]

In the dashboard it claims the wrangler.toml file should be used instead?

[evanderkoogh]

There are 2 ways to configure environment variables. If you use wrangler to deploy, you need to configure everything in wrangler.toml and if you don't, you need to use the Dashboard.