docs: start databricks page

Part of #4724

content/docs/sidebar.json

@@ -213,6 +213,10 @@
           {
             "label": "Amazon SageMaker",
             "slug": "sagemaker"
+          },
+          {
+            "label": "Databricks",
+            "slug": "databricks"
           }
         ]
       },

content/docs/user-guide/integrations/databricks.md

@@ -0,0 +1,47 @@
+# Databricks
+
+As of September 2023 Databricks doesn't expose the underlying GIT repo in your
+project, so GIT-related DVC functionality within the repo provided by Databricks
+is not supported (e.g. [experiments], `--rev/--all-commits/--all-tags/etc`). But
+everything will operate as normal if you `git clone` a project yourself or use
+remote projects with DVC directly.
+
+## Install
+
+```bash
+%pip install dvc
+```
+
+## DVC API
+
+You can use your existing DVC projects through [Python API] as normal.
+
+### Secrets
+
+If you need to use secrets to access your data, first add them to databricks
+secrets https://docs.databricks.com/en/security/secrets/index.html and then use
+them with DVC, for example:
+
+```python
+import dvc.api
+
+remote_config = {
+    "access_key_id": dbutils.secrets.get(scope="test_scope", key="aws_access_key_id"),
+    "secret_access_key": dbutils.secrets.get(scope="test_scope", key="aws_secret_access_key"),
+}
+
+mydataregistry = "https://github.com/efiop/mydataregistry"
+
+with dvc.api.open("recent-grads.csv", repo=mydataregistry, remote_config=remote_config) as fobj:
+    ...
+```
+
+## Running DVC commands
+
+Databricks doesn't provide a classic terminal, so you'll need to use [magic
+commands] to run it, e.g. `!dvc add data`.
+
+[experiments]: /doc/start/experiments
+[Python API]: /doc/api-reference
+[magic commands]:
+  https://ipython.readthedocs.io/en/stable/interactive/magics.html