docs: simplify auth flow and remove get-api-url step (#40)

Author: msaroufim

README.md

@@ -52,12 +52,10 @@ After installation, restart your terminal (or run `source ~/.bashrc` / `source ~
 
 Since we're effectively giving out GPUs for free we rely on either github or discord authentication to prove that you're a real human before you access our service.
 
-1. Go to the [GPU Mode Discord server](https://discord.gg/gpumode) and type in `/get-api-url`
-2. Copy paste that url out `export POPCORN_API_URL="result_of_get_api_url"`
-3. We recommend you authenticate via your Discord as this will guarantee that your name will show up correctly on the leaderboard, you can do this via `popcorn-cli register discord`. However in case this doesn't work for you we also support Github based authentication with `popcorn-cli register github`
-4. To ensure the above worked you can run `cat $HOME/.popcorn.yaml` which should print your client ID which is what will be sent to us on every request
+1. Register the CLI (Discord recommended): `popcorn register discord` (or `popcorn register github`)
+2. To ensure the above worked you can run `cat $HOME/.popcorn.yaml` which should print your client ID which is what will be sent to us on every request
 
-Sometimes you'll get an error that you're already authenticated despite being unable to submit in which case you can run `popcorn-cli reregister [discord|github]`.
+Sometimes you'll get an error that you're already authenticated despite being unable to submit in which case you can run `popcorn reregister [discord|github]`.
 
 ## Make your first submission