DO notes in heroku migration doc

Author: jordanstephens

docs/tutorials/migrating-from-heroku.md

@@ -350,6 +350,24 @@ GCP_PROJECT_ID=my-project-123456 defang compose up --provider gcp
 ```
 </details>
 
+### Deploying to DigitalOcean
+
+If you're deploying to GCP, you'll need to invoke `defang compose up --provider digitalocean` with your DigitalOcean access credentials in the environment:
+
+:::warning
+Some Heroku applications may require some manual adjustments to be deployed to DigitalOcean with Defang.
+Defang does not yet support deployments to DigitalOcean without a Dockerfile, so you will need to create one.
+Defang also does not yet support release tasks on DigitalOcean, so you will need to modify your services to run these tasks during initialization.
+:::
+
+```
+export DIGITALOCEAN_TOKEN=your_digitalocean_token
+export SPACES_ACCESS_KEY_ID=your_spaces_access_key_id
+export SPACES_SECRET_ACCESS_KEY=your_spaces_secret_access_key
+$ defang compose up --provider digitalocean
+```
+
+
 ## Step 3 - Migrating your data
 
 :::tip