feat(s3): implement non-ephemeral storage through S3/DO Spaces

docs/docs/source-code/env-vars.mdx

@@ -161,3 +161,31 @@ You can get your own key here: https://docs.sendgrid.com/ui/account-and-settings
 
 **Required**: `no`  
 **Description:** Sender's Email Address
+
+## Storage
+
+You can either use S3 or any S3-compliant service such as DigitalOcean Spaces to store profile pictures uploaded by users of the platform.
+
+### `STORAGE_BUCKET`
+
+**Required**: `yes`
+
+### `STORAGE_REGION`
+
+**Required**: `yes`
+
+### `STORAGE_ENDPOINT`
+
+**Required**: `yes`
+
+### `STORAGE_URL_PREFIX`
+
+**Required**: `yes`
+
+### `STORAGE_ACCESS_KEY`
+
+**Required**: `yes`
+
+### `STORAGE_SECRET_KEY`
+
+**Required**: `yes`