Update README.md (#2282)

README.md

@@ -72,6 +72,8 @@ finally, to run the web app only, run:
 yarn start
 ```
 
+If you're not an KittyCAD employee you won't be able to access the dev environment, you should copy everything from `.env.production` to `.env.development` to make it point to production instead, then when you navigate to `localhost:3000` the easiest way to sign in is to paste `localStorage.setItem('TOKEN_PERSIST_KEY', "your-token-from-https://zoo.dev/account/api-tokens")` replacing the with a real token from https://zoo.dev/account/api-tokens ofcourse, then navigate to localhost:3000 again. Note that navigating to localhost:3000/signin removes your token so you will need to set the token again.
+
 ### Development environment variables
 
 The Copilot LSP plugin in the editor requires a Zoo API token to run. In production, we authenticate this with a token via cookie in the browser and device auth token in the desktop environment, but this token is inaccessible in the dev browser version because the cookie is considered "cross-site" (from `localhost` to `dev.zoo.dev`). There is an optional environment variable called `VITE_KC_DEV_TOKEN` that you can populate with a dev token in a `.env.development.local` file to not check it into Git, which will use that token instead of other methods for the LSP service.