Add Snowflake warehouse error message environment variable (#366)

* Update self-host/customize-deployment/environment-variables.mdx

Co-Authored-By: mintlify[bot] <109931778+mintlify[bot]@users.noreply.github.com>

* Update self-host/customize-deployment/environment-variables.mdx

Co-Authored-By: mintlify[bot] <109931778+mintlify[bot]@users.noreply.github.com>

---------

Co-authored-by: mintlify[bot] <109931778+mintlify[bot]@users.noreply.github.com>

Author: mintlify[bot]

self-host/customize-deployment/environment-variables.mdx

@@ -54,6 +54,13 @@ This is a reference to all environment variables that can be used to configure a
 
 Lightdash also accepts all [standard postgres environment variables](https://www.postgresql.org/docs/9.3/libpq-envars.html)
 
+## Snowflake
+
+| Variable                                | Description                                                                                                                                                                                                     |
+| :-------------------------------------- | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `SNOWFLAKE_WAREHOUSE_ERROR_MESSAGE`     | Custom error message displayed when users encounter Snowflake warehouse access errors. Use `{warehouseName}` as a placeholder for the actual warehouse name. Example: `You don't have access to warehouse {warehouseName}. Please reach out to your admin.` |
+| `SNOWFLAKE_UNAUTHORIZED_ERROR_MESSAGE`  | Custom error message displayed when users encounter Snowflake authorization errors (e.g., "Object does not exist or not authorized"). Use `{snowflakeTable}` and `{snowflakeSchema}` as placeholders. Example: `You don't have access to the {snowflakeTable} table. Please go to '{snowflakeSchema}' and request access.` |
+
 ## SMTP
 
 This is a reference to all the SMTP environment variables that can be used to configure a Lightdash email client.