docs: clarify next-auth instructions (vercel#85)

.env.example

@@ -1,14 +1,16 @@
-## You must first activate a Billing Account here: https://platform.openai.com/account/billing/overview
-## Then get your OpenAI API Key here: https://platform.openai.com/account/api-keys
+# You must first activate a Billing Account here: https://platform.openai.com/account/billing/overview
+# Then get your OpenAI API Key here: https://platform.openai.com/account/api-keys
 OPENAI_API_KEY=XXXXXXXX
 
-## Generate a random secret: https://generate-secret.vercel.app/32 or `openssl rand -base64 32`
+# Generate a random secret: https://generate-secret.vercel.app/32 or `openssl rand -base64 32`
 AUTH_SECRET=XXXXXXXX
-## Create a GitHub OAuth app here: https://docs.github.com/en/apps/oauth-apps/building-oauth-apps/creating-an-oauth-app
+# Create a GitHub OAuth app here: https://github.com/settings/applications/new
+# Authorization callback URL: https://authjs.dev/reference/core/providers_github#callback-url
 AUTH_GITHUB_ID=XXXXXXXX
 AUTH_GITHUB_SECRET=XXXXXXXX
-## Support OAuth login on preview deployments, see: https://authjs.dev/guides/basics/deployment#securing-a-preview-deployment
-AUTH_REDIRECT_PROXY_URL=https://auth.example.com/api/auth
+# Support OAuth login on preview deployments, see: https://authjs.dev/guides/basics/deployment#securing-a-preview-deployment
+# Set the following only when deployed. We recommend using a different OAuth app for development/production.
+# AUTH_REDIRECT_PROXY_URL=https://auth.example.com/api/auth
 
 # Instructions to create kv database here: https://vercel.com/docs/storage/vercel-kv/quickstart and 
 KV_URL=XXXXXXXX

README.md

@@ -28,7 +28,7 @@
   - [Radix UI](https://radix-ui.com) for headless component primitives
   - Icons from [Phosphor Icons](https://phosphoricons.com)
 - Chat History, rate limiting, and session storage with [Vercel KV](https://vercel.com/storage/kv)
-- [Next Auth](https://github.com/nextauthjs/next-auth) for authentication
+- [NextAuth.js](https://github.com/nextauthjs/next-auth) for authentication
 
 ## Model Providers