adds docs for next-auth trust host

docs/docs/deploy/environment-variables.md

@@ -96,6 +96,7 @@ These environment variables are loaded when running the `mgmt migrate up` comman
 | AUTH_AUTHORIZE_URL        | The full url that routes to the authorize url. This is optional and may be necessary if you're using AUTH_EXPECTED_ISSUER as the urls will be different. This will need to include the public url (same value as AUTH_EXPECTED_ISSUER). If using a fully external auth provider, this will most likely not be needed.                             | false       |                           |
 | AUTH_USERINFO_URL         | The full url that routes to the userinfo url. This is optional and may be necessary if you're using AUTH_EXPECTED_ISSUER as the urls will be different. This will most likely need to include the internal url (same value as AUTH_ISSUER). If using a fully external auth provider, this will most likely not be needed.                         | false       |                           |
 | AUTH_TOKEN_URL            | The full url that routes to the token url. This is optional and may be necessary if you're using AUTH_EXPECTED_ISSUER as the urls will be different. This will most likely need to include the internal url (same value as AUTH_ISSUER). If using a fully external auth provider, this will most likely not be needed.                            | false       |                           |
+| AUTH_TRUST_HOST           | Whether or not to trust the external host. Check the next-auth docs for more details. This is pretty must required if running behind a load balancer.                                                                                                                                                                                             | true        |                           |
 | NEOSYNC_ANALYTICS_ENABLED | Enables analytics within the Neosync app. Disable to turn off all analytics.                                                                                                                                                                                                                                                                      | false       | true                      |
 | POSTHOG_KEY               | API key used to send analytics to Posthog. Without this, analytics will be disabled, even if `NEOSYNC_ANALYTICS_ENABLED` is set to true.                                                                                                                                                                                                          | false       | Neosync's posthog api key |
 | POSTHOG_HOST              | Used to change the host of the Posthog instance that analytics are shipped to. Only needed if self-hosting Posthog or not shipping to the default Posthog platform.                                                                                                                                                                               | false       | https://app.posthog.com   |