MVP for Google BigQuery docs (#966)

Author: seanparkross

docs/data-sources/connect-to-a-source.mdx

@@ -49,6 +49,20 @@ it requires:
 
 <Tabs groupId="source-preference" className="api-tabs">
 
+<TabItem value="BigQuery" label="BigQuery">
+
+| ENV        | Example                                                                                                                                                                                               | Description                                       |
+| ---------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------- |
+| `JDBC_URL` | `jdbc:bigquery://https://www.googleapis.com/bigquery/v2:443;ProjectId=project-id;DefaultDataset=dataset;OAuthType=0;OAuthServiceAcctEmail=service-account-email;OAuthPvtKey=/etc/connector/key.json;` | The JDBC URL to connect to the BigQuery database. |
+
+:::info BigQuery specific characteristics
+
+See [here](/how-to-build-with-ddn/with-bigquery.mdx) for instructions on saving your service account key file
+
+:::
+
+</TabItem>
+
 <TabItem value="ClickHouse" label="ClickHouse">
 
 | ENV                 | Example             | Description                                               |