selfhosted-guide: make it clear when to run configure.sh (#419)

Author: nazarewk

src/pages/selfhosted/selfhosted-guide.mdx

@@ -73,6 +73,10 @@ NETBIRD_AUTH_DEVICE_AUTH_CLIENT_ID=""
 NETBIRD_LETSENCRYPT_EMAIL=""
 ```
 
+<Note>
+    The changes made to `setup.env` will not take any effect until you run `configure.sh` (mentioned later on).
+</Note>
+
 - Set ```NETBIRD_DOMAIN``` to your domain, e.g.  `demo.netbird.io`
 - Configure ```NETBIRD_LETSENCRYPT_EMAIL``` property.
 This can be any email address. [Let's Encrypt](https://letsencrypt.org/) will create an account while generating a new certificate.
@@ -124,6 +128,10 @@ Make sure all the required properties set in the ```setup.env``` file and run:
 
 This will export all the properties as environment variables and generate ```artifacts/docker-compose.yml```, ```artifacts/management.json``` and ```artifacts/turnserver.conf``` files substituting required variables.
 
+<Note>
+    The changes made to `setup.env` will not take any effect until you run `configure.sh` again
+</Note>
+
 ### Step 6: Run docker compose:
 
 ```bash